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  • Parameter error with Mysqli

    - by Morgan Green
    When I run this Query I recieve Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given in /home/morgan58/public_html/wow/includes/index/index_admin.php on line 188 SELECT * FROM characters WHERE id=5 Warning: mysqli_free_result() expects parameter 1 to be mysqli_result, boolean given in /home/morgan58/public_html/wow/includes/index/index_admin.php on line 194 The Query is running and it is strying to select the correct information, but for on the actual output it's giving me a fetch_array error; if anyone can see where the error lies it'd be much appreciated. Thank you. <?php $adminid= $admin->get_id(); $characterdb= 'characters'; $link = mysqli_connect("$server", "$user", "$pass", "$characterdb"); if (mysqli_connect_errno()) { printf("Connect failed: %s\n", mysqli_connect_error()); exit(); } $query = "SELECT * FROM characters WHERE id=$adminid"; $result = mysqli_query($link, $query); while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) { echo $query; echo $row['name']; } mysqli_free_result($result); mysqli_close($link); ?>

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  • i don't know how to solve this error

    - by wide
    in local it works. when i load server, i got this error. Using themed css files requires a header control on the page. (e.g. <head runat="server" />). Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.InvalidOperationException: Using themed css files requires a header control on the page. (e.g. <head runat="server" />). Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Stack Trace: [InvalidOperationException: Using themed css files requires a header control on the page. (e.g. <head runat="server" />).] System.Web.UI.PageTheme.SetStyleSheet() +2458406 System.Web.UI.Page.OnInit(EventArgs e) +8699420 System.Web.UI.Control.InitRecursive(Control namingContainer) +333 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +378

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  • Need access to views on the OnSeekBarChangeListener (which is in an own class)

    - by sandkasten
    first of all I hope you understand my english because I'am not a native speaker. Okay, I'am new to android development and try following: For my app I need a SeekBar, so I create a Seekbar via XML and implement an OnSeekBarChangeListener. In the compay I work for its forbidden (because of the styleguid) to create something like this: seekbar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() { @Override public void onProgressChanged(SeekBar arg0, int arg1, boolean arg2) { /// Do something } ... }); So I need to create a own class for the OnSeekBarChangeListener. So far no problem. public class SeekBarChangeListener extends SeekBar implements SeekBar.OnSeekBarChangeListener { public SeekBarChangeListener(Context context) { super(context); } public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { } public void onStartTrackingTouch(SeekBar seekBar) { } public void onStopTrackingTouch(SeekBar seekBar) { /// Do something. Following Code wont work CheckBox RemeberUsername = (CheckBox)findViewById(R.id.RemeberUsername); /// Always gets NULL } } I need a way to get access to some controls. Normaly the findViewById works fine but not in this case (what I can totaly understand, because how should the listender know about the views?). Some good hints? Or is there no oter way like the first code snippet to get the controls? Hope someone can help me out.

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  • Java: "cannot find symbol" error of a String[] defined within a while-loop

    - by David
    Here's the relevant code: public static String[] runTeams (String CPUcolor) { boolean z = false ; //String[] a = new String[6] ; boolean CPU = false ; while (z == false) { while (CPU==false) { String[] a = assignTeams () ; printOrder (a) ; for (int i = 1; i<a.length; i++) { if (a[i].equals(CPUcolor)) CPU = true ; } if (CPU==false) { System.out.println ("ERROR YOU NEED TO INCLUDE THE COLOR OF THE CPU IN THE TURN ORDER") ; } } System.out.println ("is this turn order correct? (Y/N)") ; String s = getIns () ; while (!((s.equals ("y")) || (s.equals ("Y")) || (s.equals ("n")) || (s.equals ("N")))) { System.out.println ("try again") ; s = getIns () ; } if (s.equals ("y") || s.equals ("Y") ) z = true ; } return a ; } the error i get is: Risk.java:416: cannot find symbol symbol : variable a location: class Risk return a ; ^ Why did i get this error? It seems that a is clearly defined in the line String[] a = assignTeams () ; and if anything is used by the lineprintOrder (a) ;` it seems to me that if the symbol a really couldn't be found then the compiler should blow up there and not at the return statment. (also the method assignTeams returns an array of Strings.)

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  • How can I get a default value in some instances but not others?

    - by Connor Wagner
    I am making an iPhone app and want to use an 'if' statement and a boolean to set default values in some instances but not others... is this possible? Are there alternative options if it is not possible? In the MainViewController.m I have: @interface MainViewController (){ BOOL moveOver; } [...] - (void)viewDidLoad { [super viewDidLoad]; _label.text = [NSString stringWithFormat:@"%i", computerSpeed]; } } [...] - (void)flipsideViewControllerDidFinish:(FlipsideViewController *)controller { [self dismissViewControllerAnimated:YES completion:nil]; moveOver = true; } The problem that it is redefined when the ViewDidLoad runs... I need a statement that will not redefine when the ViewDidLoad runs. I have something that I feel like is much closer to working... In the ViewDidLoad I have: if (playToInt != 10 || computerMoveSpeed != 3) { moveOver = TRUE; } which connects to my created method, gameLoop. It has if (moveOver == false) { computerMoveSpeed = 3; playToInt = 10; } I have tried putting the code in the gameLoop into the ViewDidLoad, but it had the same effect. When moveOver was false, the computerMoveSpeed and the playToInt were both seemingly 0. I have two UITextFields and typed 10 and 3 in them... does this not set it to the default? It seems to set the default to 0 for both, how do I change this? THIS IS A DIFFERENT ISSUE THAN THE THREE BOOLEAN VALUES QUESTION

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  • junit test error - ClassCastException

    - by Josepth Vodary
    When trying to run a junit test I get the following error - java.lang.ClassCastException: business.Factory cannot be cast to services.itemservice.IItemsService at business.ItemManager.get(ItemManager.java:56) at business.ItemMgrTest.testGet(ItemMgrTest.java:49) The specific test that is causing the problem is @Test public void testGet() { Assert.assertTrue(itemmgr.get(items)); } The code it is testing is... public boolean get(Items item) { boolean gotItems = false; Factory factory = Factory.getInstance(); @SuppressWarnings("static-access") IItemsService getItem = (IItemsService)factory.getInstance(); try { getItem.getItems("pens", 15, "red", "gel"); gotItems = true; } catch (ItemNotFoundException e) { // catch e.printStackTrace(); System.out.println("Error - Item Not Found"); } return gotItems; } The test to store items, which is nearly identical, works just fine... The factory class is.. public class Factory { private Factory() {} private static Factory Factory = new Factory(); public static Factory getInstance() {return Factory;} public static IService getService(String serviceName) throws ServiceLoadException { try { Class<?> c = Class.forName(getImplName(serviceName)); return (IService)c.newInstance(); } catch (Exception e) { throw new ServiceLoadException(serviceName + "not loaded"); } } private static String getImplName (String serviceName) throws Exception { java.util.Properties props = new java.util.Properties(); java.io.FileInputStream fis = new java.io.FileInputStream("config\\application.properties"); props.load(fis); fis.close(); return props.getProperty(serviceName); } }

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  • Patterns to deal with with functions that can have different kinds of results.

    - by KaptajnKold
    Suppose you have an method on an object that given the some input alters the objects state if the input validates according to some complex logic. Now suppose that when the input doesn't validate, it can be due to several different things, each of which we would like to be able to deal with in different ways. I'm sure many of you are thinking: That's what exceptions are for! I've thought of this also. But my reservation against using exceptions is that in some cases there is nothing exceptional about the input not validating and I really would like to avoid using exceptions to control what is really just in the expected flow of the program. If there were only one interpretation possible, I could simply choose to return a boolean value indicating whether or not the operation resulted in a state change or not and the respond appropriately when it did not. There is of course also the option to return a status code which the client can then choose to interpret or not. I don't like this much either because there is nothing semantic about status codes. The solution I have so far is to always check for each possible situation which I am able to handle before I call the method which then returns a boolean to inform the client if the object changed state. This leaves me the flexibility to handle as few or as many as the possible situations as I wish depending on the context I am in. It also has the benefit of making the method I am calling simpler to write. The drawback is that there is quite a lot of duplication in the client code wherever I call the method. Which of these solutions do you prefer and why? What other patterns do people use for providing meaningful feedback from functions? I know that some languages support multiple return values, and I if I had that option I would surely prefer it.

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  • Validation Logic

    - by user2961971
    I am trying to create some validation for a form I have. There are two text boxes and two radio buttons on the form. My logic for this validation I know is a little rusty at the moment so any suggestions would be great. Here is the code for what I have so far: Keep in mind that the int errors is a public variable in the class Start Button code: private void btnStart_Click(object sender, EventArgs e) { errors = validateForm(); //Here I want the user to be able to fix any errors where I am little stuck on that logic at the moment //validate the form while (errors > 0) { validateForm(); errors = validateForm(); } } ValidateForm Method: private int validateForm() { errors = 0; //check the form if there are any unentered values if (txtDest.Text == "") { errors++; } if (txtExt.Text == "") { errors++; } if (validateRadioBtns() == true) { errors++; } return errors; } ValidateRadioBtns Method: private Boolean validateRadioBtns() { //flag - false: selected, true: none selected Boolean blnFlag = false; //both of the radio buttons are unchecked if (radAll.Checked == false && radOther.Checked == false) { blnFlag = true; } //check if there is a value entered in the text box if other is checked else if(radOther.Checked == true && txtExt.Text == "") { blnFlag = true; } return blnFlag; } Overall I feel like this can somehow be more stream lined which I am fairly stuck on. Also, I am stuck on how to ensure the user can return to the form, fix the errors, and then validate again to ensure said errors are fixed. Any suggestions would be greatly appreciated since I know this is such a nooby question.

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  • public String shorthand(String in)

    - by luvthug
    Hi All, I am stuck on this code. The code should use the class StringBuilder to build an output string by appending non-vowel characters from its argument in to the result it returns. It needs to identify vowels to be removed using the helper metod i created which is public boolean isVowel(char c). public String shorthand(String in) this is the method I need help with. I have created the stringbuilder but the if condition does not accept isVowel method. import java.io.*; import java.util.*; public class Shorthand { public boolean isVowel(char c) { if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u' || c == 'A'|| c == 'E'||c == 'I'|| c == 'O'|| c == 'U') { return true; } else { return false; } } //TODO Complete the shorthand method public String shorthand(String in) //this is the code I need help with { StringBuilder vowel = new StringBuilder(); if (isVowel() == false)strong text { vowel.append(in); } return vowel.toString(); } //TODO Complete the run method public void run() throws IOException { String yourLine; Scanner sc = new Scanner(System.in); yourLine = sc.nextLine(); while(!yourLine.equals("*")); { System.out.println("Enter your line of text"); } yourLine = sc.nextLine(); } }

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  • Cannot Display Data from MySQL table

    - by MxmastaMills
    I've got a pretty standard call to a MySQL database and for some reason I can't get the code to work. Here's what I have: $mysqli = mysqli_connect("localhost","username","password"); if (!$mysqli) { die('Could not connect: ' . mysqli_error($mysqli)); } session_start(); $sql = "SELECT * FROM jobs ORDER BY id DESC"; $result = $mysqli->query($sql); $num_rows = mysqli_num_rows($result); Now, first, I know that it is connecting properly because I'm not getting the die method plus I added an else conditional in there previously and it checked out. Then the page displays but I get the errors: Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given in blablabla/index.php on line 11 Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given in blablabla/index.php on line 12 I've double-checked my database and there is a table called jobs with a row of "id" (it's the primary row). The thing that confuses me is this is code that I literally copied and pasted from another site I built and for some reason the code doesn't work on this one (I obviously copy and pasted it and then just changed the table name and rows accordingly). I saw the error and tried: $num_rows = $mysqli_result->num_rows; $row_array = $mysqli_result->fetch_array; and that fixed the errors but resulted in no data being passed (because obviously $mysqli_result has no value). I don't know why the error is calling for that (is it a difference in version of MySQL or PHP from the other site)? Can someone help me track down the problem? Thanks so much. Sorry if it's something super simple that I'm overlooking, I've been at it for a while.

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  • Performing a MYSQL query based off of $_GET results

    - by Michael N
    When a user clicks an item on my items page, it takes them to blank page template using $_GET to pass the item brand and model through. I'd like to perform another MYSQL query when that user clicks through to populate the blank page with the product details from my database. I'd like to retrieve the single row using the model number (unique ID) to populate the page with the information. I've tried a couple of things but am having a little difficulty. On my blank item page, I have $brand = $_GET['Brand']; $modelnumber = $_GET['ModelNumber']; $query = mysql_query("SELECT * FROM items WHERE `Model Number` = '$modelnumber'"); $results = mysql_fetch_row($query); echo $results; I think having ''s around Model Number is causing troubles, but without them, I get a Warning: mysql_fetch_row() expects parameter 1 to be resource, boolean given error. My database columns looks like Brand | Model Number | Price | Description | Image A few other things I have tried include $query = mysql_query("SELECT * FROM item WHERE Model Number = $_GET['ModelNumber']"); Which gave me a syntax error. I've also tried concatenating the $_GET which gives me a mysql_fetch_row() expects parameter 1 to be resource, boolean given error Which leads me to believe that I'm also going about displaying the results incorrectly. I'm not sure if I need to put it in a where loop like I have with my previous page which displays all items in the database because this is just displaying one.

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  • Runtime of optimized Primehunter

    - by Setton
    Ok so I need some serious runtime help here! This method should take in an int value, check its primality, and return true if the number is indeed a prime. I understand why the loop only needs to go up to i squared, I understand that the worst case scenario is the case in which either the number is prime (or a multiple of a prime). But I don't understand how to quantify the actual runtime. I have done the loop myself by hand to try to understand the pattern or correlation of the number (n) and how many loops occur, but I literally feel like I keep falling into the same trap every time. I need a new way of thinking about this! I have a hint: "Think about the SIZE of the integer" which makes me want to quantify the literal number of integers in a number in relation to how many iterations it does in the for loop (floor log(n)) +1). BUT IT'S NOT WORKIIIING?! I KNOW it isn't square root n, obviously. I'm asking for Big O notation. public class PrimeHunter { public static boolean isPrime(int n) { boolean answer = (n > 1) ? true : false; //runtime = linear runtime for (int i = 2; i * i <= n; i++) //runtime = ????? { if (n % i == 0) //doesn't occur if it is a prime { answer = false; break; } } return answer; //runtime = linear runtime } }

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  • Delphi Editbox causing unexplainable errors...

    - by NeoNMD
    On a form I have 8 edit boxes that I do the exact same thing with. They are arranged in 2 sets of 4, one is Upper and the other is Lower. I kept getting errors clearing all the edit boxes so I went through clearing them 1 by 1 and found that 1 of the edit boxes just didnt work and when I tried to run the program and change that exit box it caused the debugger to jump to a point in the code with the database (even though the edit boxes had nothing to do with the database and they arent in a procedure or stack with a database in it) and say the program has access violation there. So I then removed all mention of that edit box and the code worked perfectly again, so I deleted that edit box, copied and pasted another edit box and left all values the same, then went through my code and copied the code from the other sections and simply renamed it for the new Edit box and it STILL causes an error even though it is entirely new. I cannot figure it out so I ask you all, what the hell? The editbox in question is "Edit1" unit DefinitionCoreV2; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, SQLiteTable3, StdCtrls; type TDefinitionFrm = class(TForm) GrpCompetition: TGroupBox; CmbCompSele: TComboBox; BtnCompetitionAdd: TButton; BtnCompetitionUpdate: TButton; BtnCompetitionRevert: TButton; GrpCompetitionDetails: TGroupBox; LblCompetitionIDTitle: TLabel; EdtCompID: TEdit; LblCompetitionDescriptionTitle: TLabel; EdtCompDesc: TEdit; LblCompetitionNotesTitle: TLabel; EdtCompNote: TEdit; LblCompetitionLocationTitle: TLabel; EdtCompLoca: TEdit; BtnCompetitionDelete: TButton; GrpSection: TGroupBox; LblSectionID: TLabel; LblGender: TLabel; LblAge: TLabel; LblLevel: TLabel; LblWeight: TLabel; LblType: TLabel; LblHeight: TLabel; LblCompetitionID: TLabel; BtnSectionAdd: TButton; EdtSectionID: TEdit; CmbGender: TComboBox; BtnSectionUpdate: TButton; BtnSectionRevert: TButton; CmbAgeRange: TComboBox; CmbLevelRange: TComboBox; CmbType: TComboBox; CmbWeightRange: TComboBox; CmbHeightRange: TComboBox; EdtSectCompetitionID: TEdit; BtnSectionDelete: TButton; GrpSectionDetails: TGroupBox; EdtLowerAge: TEdit; EdtLowerWeight: TEdit; EdtLowerHeight: TEdit; EdtUpperAge: TEdit; EdtUpperLevel: TEdit; EdtUpperWeight: TEdit; EdtUpperHeight: TEdit; LblAgeRule: TLabel; LblLevelRule: TLabel; LblWeightRule: TLabel; LblHeightRule: TLabel; LblCompetitionSelect: TLabel; LblSectionSelect: TLabel; CmbSectSele: TComboBox; Edit1: TEdit; procedure FormCreate(Sender: TObject); procedure BtnCompetitionAddClick(Sender: TObject); procedure CmbCompSeleChange(Sender: TObject); procedure BtnCompetitionUpdateClick(Sender: TObject); procedure BtnCompetitionRevertClick(Sender: TObject); procedure BtnCompetitionDeleteClick(Sender: TObject); procedure CmbSectSeleChange(Sender: TObject); procedure BtnSectionAddClick(Sender: TObject); procedure BtnSectionUpdateClick(Sender: TObject); procedure BtnSectionRevertClick(Sender: TObject); procedure BtnSectionDeleteClick(Sender: TObject); procedure CmbAgeRangeChange(Sender: TObject); procedure CmbLevelRangeChange(Sender: TObject); procedure CmbWeightRangeChange(Sender: TObject); procedure CmbHeightRangeChange(Sender: TObject); private procedure UpdateCmbCompSele; procedure AddComp; procedure RevertComp; procedure AddSect; procedure RevertSect; procedure UpdateCmbSectSele; procedure ClearSect; { Private declarations } public { Public declarations } end; var DefinitionFrm: TDefinitionFrm; implementation {$R *.dfm} procedure TDefinitionFrm.UpdateCmbCompSele; var slDBpath: string; sldb : TSQLiteDatabase; sltb : TSQLiteTable; sCompTitle : string; bNext : boolean; begin slDBPath := ExtractFilepath(application.exename)+ 'Competitions.db'; if not FileExists(slDBPath) then begin MessageDlg('Competitions.db does not exist.',mtInformation,[mbOK],0); exit; end; sldb := TSQLiteDatabase.Create(slDBPath); try sltb := slDb.GetTable('SELECT * FROM CompetitionTable'); try CmbCompSele.Items.Clear; Repeat begin sCompTitle:=sltb.FieldAsString(sltb.FieldIndex['CompetitionID'])+':'+sltb.FieldAsString(sltb.FieldIndex['Description']); CmbCompSele.Items.Add(sCompTitle); bNext := sltb.Next; end; Until sltb.EOF; finally sltb.Free; end; finally sldb.Free; end; end; procedure TDefinitionFrm.UpdateCmbSectSele; var slDBpath: string; sldb : TSQLiteDatabase; sltb : TSQLiteTable; sSQL : string; sSectTitle : string; bNext : boolean; bLast : boolean; begin slDBPath := ExtractFilepath(application.exename)+ 'Competitions.db'; if not FileExists(slDBPath) then begin MessageDlg('Competitions.db does not exist.',mtInformation,[mbOK],0); exit; end; sldb := TSQLiteDatabase.Create(slDBPath); try sltb := slDb.GetTable('SELECT * FROM SectionTable WHERE CompetitionID = '+EdtCompID.text); If sltb.RowCount =0 then begin sltb := slDb.GetTable('SELECT * FROM SectionTable'); bLast:= sltb.MoveLast; sSQL := 'INSERT INTO SectionTable(SectionID,CompetitionID,Gender,Type) VALUES ('+IntToStr(sltb.FieldAsInteger(sltb.FieldIndex['SectionID'])+1)+','+EdtCompID.text+',1,1)'; sldb.ExecSQL(sSQL); sltb := slDb.GetTable('SELECT * FROM SectionTable WHERE CompetitionID = '+EdtCompID.text); end; try CmbSectSele.Items.Clear; Repeat begin sSectTitle:=sltb.FieldAsString(sltb.FieldIndex['SectionID'])+':'+sltb.FieldAsString(sltb.FieldIndex['Type'])+':'+sltb.FieldAsString(sltb.FieldIndex['Gender'])+':'+sltb.FieldAsString(sltb.FieldIndex['Age'])+':'+sltb.FieldAsString(sltb.FieldIndex['Level'])+':'+sltb.FieldAsString(sltb.FieldIndex['Weight'])+':'+sltb.FieldAsString(sltb.FieldIndex['Height']); CmbSectSele.Items.Add(sSectTitle); //CmbType.Items.Strings[sltb.FieldAsInteger(sltb.FieldIndex['Type'])] Works but has logic errors bNext := sltb.Next; end; Until sltb.EOF; finally sltb.Free; end; finally sldb.Free; end; end; procedure TDefinitionFrm.AddComp; var slDBpath: string; sSQL : string; sldb : TSQLiteDatabase; sltb : TSQLiteTable; bLast : boolean; begin slDBPath := ExtractFilepath(application.exename)+ 'Competitions.db'; if not FileExists(slDBPath) then begin MessageDlg('Competitions.db does not exist.',mtInformation,[mbOK],0); exit; end; sldb := TSQLiteDatabase.Create(slDBPath); try sltb := slDb.GetTable('SELECT * FROM CompetitionTable'); try bLast:= sltb.MoveLast; sSQL := 'INSERT INTO CompetitionTable(CompetitionID,Description) VALUES ('+IntToStr(sltb.FieldAsInteger(sltb.FieldIndex['CompetitionID'])+1)+',"New Competition")'; sldb.ExecSQL(sSQL); finally sltb.Free; end; finally sldb.Free; end; UpdateCmbCompSele; end; procedure TDefinitionFrm.AddSect; var slDBpath: string; sSQL : string; sldb : TSQLiteDatabase; sltb : TSQLiteTable; bLast : boolean; begin slDBPath := ExtractFilepath(application.exename)+ 'Competitions.db'; if not FileExists(slDBPath) then begin MessageDlg('Competitions.db does not exist.',mtInformation,[mbOK],0); exit; end; sldb := TSQLiteDatabase.Create(slDBPath); try sltb := slDb.GetTable('SELECT * FROM SectionTable'); try bLast:= sltb.MoveLast; sSQL := 'INSERT INTO SectionTable(SectionID,CompetitionID,Gender,Type) VALUES ('+IntToStr(sltb.FieldAsInteger(sltb.FieldIndex['SectionID'])+1)+','+EdtCompID.text+',1,1)'; sldb.ExecSQL(sSQL); finally sltb.Free; end; finally sldb.Free; end; UpdateCmbSectSele; end; procedure TDefinitionFrm.RevertComp; var slDBpath: string; sldb : TSQLiteDatabase; sltb : TSQLiteTable; iID : integer; begin slDBPath := ExtractFilepath(application.exename)+ 'Competitions.db'; if not FileExists(slDBPath) then begin MessageDlg('Competitions.db does not exist.',mtInformation,[mbOK],0); exit; end; sldb := TSQLiteDatabase.Create(slDBPath); try If CmbCompSele.Text <> '' then begin iID := StrToInt(Copy(CmbCompSele.Text,0,Pos(':',CmbCompSele.Text)-1)); sltb := slDb.GetTable('SELECT * FROM CompetitionTable WHERE CompetitionID='+IntToStr(iID))//ItemIndex starts at 0, CompID at 1 end else sltb := slDb.GetTable('SELECT * FROM CompetitionTable WHERE CompetitionID=1'); try EdtCompID.Text:=sltb.FieldAsString(sltb.FieldIndex['CompetitionID']); EdtCompLoca.Text:=sltb.FieldAsString(sltb.FieldIndex['Location']); EdtCompDesc.Text:=sltb.FieldAsString(sltb.FieldIndex['Description']); EdtCompNote.Text:=sltb.FieldAsString(sltb.FieldIndex['Notes']); finally sltb.Free; end; finally sldb.Free; end; end; procedure TDefinitionFrm.RevertSect; var slDBpath: string; sldb : TSQLiteDatabase; sltb : TSQLiteTable; iID : integer; sTemp : string; begin slDBPath := ExtractFilepath(application.exename)+ 'Competitions.db'; if not FileExists(slDBPath) then begin MessageDlg('Competitions.db does not exist.',mtInformation,[mbOK],0); exit; end; sldb := TSQLiteDatabase.Create(slDBPath); try If CmbCompSele.Text <> '' then begin iID := StrToInt(Copy(CmbSectSele.Text,0,Pos(':',CmbSectSele.Text)-1)); sltb := slDb.GetTable('SELECT * FROM SectionTable WHERE SectionID='+IntToStr(iID));//ItemIndex starts at 0, CompID at 1 end else sltb := slDb.GetTable('SELECT * FROM SectionTable WHERE CompetitionID='+EdtCompID.Text); try EdtSectionID.Text:=sltb.FieldAsString(sltb.FieldIndex['SectionID']); EdtSectCompetitionID.Text:=sltb.FieldAsString(sltb.FieldIndex['CompetitionID']); Case sltb.FieldAsInteger(sltb.FieldIndex['Type']) of 1 : CmbType.ItemIndex:=0; 2 : CmbType.ItemIndex:=0; 3 : CmbType.ItemIndex:=1; 4 : CmbType.ItemIndex:=1; end; Case sltb.FieldAsInteger(sltb.FieldIndex['Gender']) of 1 : CmbGender.ItemIndex:=0; 2 : CmbGender.ItemIndex:=1; 3 : CmbGender.ItemIndex:=2; end; sTemp := sltb.FieldAsString(sltb.FieldIndex['Age']); if sTemp <> '' then begin //Decode end else begin LblAgeRule.Hide; EdtLowerAge.Text :=''; EdtLowerAge.Hide; EdtUpperAge.Text :=''; EdtUpperAge.Hide; end; sTemp := sltb.FieldAsString(sltb.FieldIndex['Level']); if sTemp <> '' then begin //Decode end else begin LblLevelRule.Hide; Edit1.Text :=''; Edit1.Hide; EdtUpperLevel.Text :=''; EdtUpperLevel.Hide; end; sTemp := sltb.FieldAsString(sltb.FieldIndex['Weight']); if sTemp <> '' then begin //Decode end else begin LblWeightRule.Hide; EdtLowerWeight.Text :=''; EdtLowerWeight.Hide; EdtUpperWeight.Text :=''; EdtUpperWeight.Hide; end; sTemp := sltb.FieldAsString(sltb.FieldIndex['Height']); if sTemp <> '' then begin //Decode end else begin LblHeightRule.Hide; EdtLowerHeight.Text :=''; EdtLowerHeight.Hide; EdtUpperHeight.Text :=''; EdtUpperHeight.Hide; end; finally sltb.Free; end; finally sldb.Free; end; end; procedure TDefinitionFrm.BtnCompetitionAddClick(Sender: TObject); begin AddComp end; procedure TDefinitionFrm.ClearSect; begin CmbSectSele.Clear; EdtSectionID.Text:=''; EdtSectCompetitionID.Text:=''; CmbType.Clear; CmbGender.Clear; CmbAgeRange.Clear; EdtLowerAge.Text:=''; EdtUpperAge.Text:=''; CmbLevelRange.Clear; Edit1.Text:=''; EdtUpperLevel.Text:=''; CmbWeightRange.Clear; EdtLowerWeight.Text:=''; EdtUpperWeight.Text:=''; CmbHeightRange.Clear; EdtLowerHeight.Text:=''; EdtUpperHeight.Text:=''; end; procedure TDefinitionFrm.CmbCompSeleChange(Sender: TObject); begin If CmbCompSele.ItemIndex <> -1 then begin RevertComp; GrpSection.Enabled:=True; CmbSectSele.Clear; ClearSect; UpdateCmbSectSele; end; end; procedure TDefinitionFrm.BtnCompetitionUpdateClick(Sender: TObject); var slDBpath: string; sSQL : string; sldb : TSQLiteDatabase; begin slDBPath := ExtractFilepath(application.exename)+ 'Competitions.db'; if not FileExists(slDBPath) then begin MessageDlg('Competitions.db does not exist.',mtInformation,[mbOK],0); exit; end; sldb := TSQLiteDatabase.Create(slDBPath); try sSQL:= 'UPDATE CompetitionTable SET Description="'+EdtCompDesc.Text+'",Location="'+EdtCompLoca.Text+'",Notes="'+EdtCompNote.Text+'" WHERE CompetitionID ="'+EdtCompID.Text+'";'; sldb.ExecSQL(sSQL); finally sldb.Free; end; end; procedure TDefinitionFrm.BtnCompetitionRevertClick(Sender: TObject); begin RevertComp; end; procedure TDefinitionFrm.BtnCompetitionDeleteClick(Sender: TObject); var slDBpath: string; sSQL : string; sldb : TSQLiteDatabase; iID : integer; begin If CmbCompSele.Text <> '' then begin If (CmbCompSele.Text[1] ='1') and (CmbCompSele.Text[2] =':') then begin MessageDlg('Deleting the last record is a very bad idea :/',mtInformation,[mbOK],0); end else begin slDBPath := ExtractFilepath(application.exename)+ 'Competitions.db'; if not FileExists(slDBPath) then begin MessageDlg('Competitions.db does not exist.',mtInformation,[mbOK],0); exit; end; sldb := TSQLiteDatabase.Create(slDBPath); try iID := StrToInt(Copy(CmbCompSele.Text,0,Pos(':',CmbCompSele.Text)-1)); sSQL:= 'DELETE FROM SectionTable WHERE CompetitionID='+IntToStr(iID)+';'; sldb.ExecSQL(sSQL); sSQL:= 'DELETE FROM CompetitionTable WHERE CompetitionID='+IntToStr(iID)+';'; sldb.ExecSQL(sSQL); finally sldb.Free; end; CmbCompSele.ItemIndex:=0; UpdateCmbCompSele; RevertComp; CmbCompSele.Text:='Select Competition'; end; end; end; procedure TDefinitionFrm.FormCreate(Sender: TObject); begin UpdateCmbCompSele; end; procedure TDefinitionFrm.CmbSectSeleChange(Sender: TObject); begin RevertSect; end; procedure TDefinitionFrm.BtnSectionAddClick(Sender: TObject); begin AddSect; end; procedure TDefinitionFrm.BtnSectionUpdateClick(Sender: TObject); //change fields values var slDBpath: string; sSQL : string; sldb : TSQLiteDatabase; iTypeCode : integer; iGenderCode : integer; sAgeStr, sLevelStr, sWeightStr, sHeightStr : string; begin slDBPath := ExtractFilepath(application.exename)+ 'Competitions.db'; if not FileExists(slDBPath) then begin MessageDlg('Competitions.db does not exist.',mtInformation,[mbOK],0); exit; end; sldb := TSQLiteDatabase.Create(slDBPath); try If CmbType.Text='Fighting' then iTypeCode := 1 else iTypeCode := 3; If CmbGender.Text='Male' then iGenderCode := 1 else if CmbGender.Text='Female' then iGenderCode := 2 else iGenderCode := 3; Case CmbAgeRange.ItemIndex of 0:sAgeStr := 'o-'+EdtLowerAge.Text; 1:sAgeStr := 'u-'+EdtLowerAge.Text; 2:sAgeStr := EdtLowerAge.Text+'-'+EdtUpperAge.Text; end; Case CmbLevelRange.ItemIndex of 0:sLevelStr := 'o-'+Edit1.Text; 1:sLevelStr := 'u-'+Edit1.Text; 2:sLevelStr := Edit1.Text+'-'+EdtUpperLevel.Text; end; Case CmbWeightRange.ItemIndex of 0:sWeightStr := 'o-'+EdtLowerWeight.Text; 1:sWeightStr := 'u-'+EdtLowerWeight.Text; 2:sWeightStr := EdtLowerWeight.Text+'-'+EdtUpperWeight.Text; end; Case CmbHeightRange.ItemIndex of 0:sHeightStr := 'o-'+EdtLowerHeight.Text; 1:sHeightStr := 'u-'+EdtLowerHeight.Text; 2:sHeightStr := EdtLowerHeight.Text+'-'+EdtUpperHeight.Text; end; sSQL:= 'UPDATE SectionTable SET Type="'+IntToStr(iTypeCode)+'",Gender="'+IntToStr(iGenderCode)+'" WHERE SectionID ="'+EdtSectionID.Text+'";'; sldb.ExecSQL(sSQL); finally sldb.Free; end; end; procedure TDefinitionFrm.BtnSectionRevertClick(Sender: TObject); begin RevertSect; end; procedure TDefinitionFrm.BtnSectionDeleteClick(Sender: TObject); var slDBpath: string; sSQL : string; sldb : TSQLiteDatabase; begin If CmbSectSele.Text[1] ='1' then begin MessageDlg('Deleting the last record is a very bad idea :/',mtInformation,[mbOK],0); end else begin slDBPath := ExtractFilepath(application.exename)+ 'Competitions.db'; if not FileExists(slDBPath) then begin MessageDlg('Competitions.db does not exist.',mtInformation,[mbOK],0); exit; end; sldb := TSQLiteDatabase.Create(slDBPath); try sSQL:= 'DELETE FROM SectionTable WHERE SectionID='+CmbSectSele.Text[1]+';'; sldb.ExecSQL(sSQL); finally sldb.Free; end; CmbSectSele.ItemIndex:=0; UpdateCmbSectSele; RevertSect; CmbSectSele.Text:='Select Competition'; end; end; procedure TDefinitionFrm.CmbAgeRangeChange(Sender: TObject); begin Case CmbAgeRange.ItemIndex of 0: begin EdtLowerAge.Show; LblAgeRule.Caption:='Over and including'; LblAgeRule.Show; EdtUpperAge.Hide; end; 1: begin EdtLowerAge.Show; LblAgeRule.Caption:='Under and including'; LblAgeRule.Show; EdtUpperAge.Hide; end; 2: begin EdtLowerAge.Show; LblAgeRule.Caption:='LblAgeRule'; LblAgeRule.Hide; EdtUpperAge.Show; end; end; end; procedure TDefinitionFrm.CmbLevelRangeChange(Sender: TObject); begin Case CmbLevelRange.ItemIndex of 0: begin Edit1.Show; LblLevelRule.Caption:='Over and including'; LblLevelRule.Show; EdtUpperLevel.Hide; end; 1: begin Edit1.Show; LblLevelRule.Caption:='Under and including'; LblLevelRule.Show; EdtUpperLevel.Hide; end; 2: begin Edit1.Show; LblLevelRule.Caption:='LblLevelRule'; LblLevelRule.Hide; EdtUpperLevel.Show; end; end; end; procedure TDefinitionFrm.CmbWeightRangeChange(Sender: TObject); begin Case CmbWeightRange.ItemIndex of 0: begin EdtLowerWeight.Show; LblWeightRule.Caption:='Over and including'; LblWeightRule.Show; EdtUpperWeight.Hide; end; 1: begin EdtLowerWeight.Show; LblWeightRule.Caption:='Under and including'; LblWeightRule.Show; EdtUpperWeight.Hide; end; 2: begin EdtLowerWeight.Show; LblWeightRule.Caption:='LblWeightRule'; LblWeightRule.Hide; EdtUpperWeight.Show; end; end; end; procedure TDefinitionFrm.CmbHeightRangeChange(Sender: TObject); begin Case CmbHeightRange.ItemIndex of 0: begin EdtLowerHeight.Show; LblHeightRule.Caption:='Over and including'; LblHeightRule.Show; EdtUpperHeight.Hide; end; 1: begin EdtLowerHeight.Show; LblHeightRule.Caption:='Under and including'; LblHeightRule.Show; EdtUpperHeight.Hide; end; 2: begin EdtLowerHeight.Show; LblHeightRule.Caption:='LblHeightRule'; LblHeightRule.Hide; EdtUpperHeight.Show; end; end; end; end.

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  • Use IIS Application Initialization for keeping ASP.NET Apps alive

    - by Rick Strahl
    I've been working quite a bit with Windows Services in the recent months, and well, it turns out that Windows Services are quite a bear to debug, deploy, update and maintain. The process of getting services set up,  debugged and updated is a major chore that has to be extensively documented and or automated specifically. On most projects when a service is built, people end up scrambling for the right 'process' to use for administration. Web app deployment and maintenance on the other hand are common and well understood today, as we are constantly dealing with Web apps. There's plenty of infrastructure and tooling built into Web Tools like Visual Studio to facilitate the process. By comparison Windows Services or anything self-hosted for that matter seems convoluted.In fact, in a recent blog post I mentioned that on a recent project I'd been using self-hosting for SignalR inside of a Windows service, because the application is in fact a 'service' that also needs to send out lots of messages via SignalR. But the reality is that it could just as well be an IIS application with a service component that runs in the background. Either way you look at it, it's either a Windows Service with a built in Web Server, or an IIS application running a Service application, neither of which follows the standard Service or Web App template.Personally I much prefer Web applications. Running inside of IIS I get all the benefits of the IIS platform including service lifetime management (crash and restart), controlled shutdowns, the whole security infrastructure including easy certificate support, hot-swapping of code and the the ability to publish directly to IIS from within Visual Studio with ease.Because of these benefits we set out to move from the self hosted service into an ASP.NET Web app instead.The Missing Link for ASP.NET as a Service: Auto-LoadingI've had moments in the past where I wanted to run a 'service like' application in ASP.NET because when you think about it, it's so much easier to control a Web application remotely. Services are locked into start/stop operations, but if you host inside of a Web app you can write your own ticket and control it from anywhere. In fact nearly 10 years ago I built a background scheduling application that ran inside of ASP.NET and it worked great and it's still running doing its job today.The tricky part for running an app as a service inside of IIS then and now, is how to get IIS and ASP.NET launched so your 'service' stays alive even after an Application Pool reset. 7 years ago I faked it by using a web monitor (my own West Wind Web Monitor app) I was running anyway to monitor my various web sites for uptime, and having the monitor ping my 'service' every 20 seconds to effectively keep ASP.NET alive or fire it back up after a reload. I used a simple scheduler class that also includes some logic for 'self-reloading'. Hacky for sure, but it worked reliably.Luckily today it's much easier and more integrated to get IIS to launch ASP.NET as soon as an Application Pool is started by using the Application Initialization Module. The Application Initialization Module basically allows you to turn on Preloading on the Application Pool and the Site/IIS App, which essentially fires a request through the IIS pipeline as soon as the Application Pool has been launched. This means that effectively your ASP.NET app becomes active immediately, Application_Start is fired making sure your app stays up and running at all times. All the other features like Application Pool recycling and auto-shutdown after idle time still work, but IIS will then always immediately re-launch the application.Getting started with Application InitializationAs of IIS 8 Application Initialization is part of the IIS feature set. For IIS 7 and 7.5 there's a separate download available via Web Platform Installer. Using IIS 8 Application Initialization is an optional install component in Windows or the Windows Server Role Manager: This is an optional component so make sure you explicitly select it.IIS Configuration for Application InitializationInitialization needs to be applied on the Application Pool as well as the IIS Application level. As of IIS 8 these settings can be made through the IIS Administration console.Start with the Application Pool:Here you need to set both the Start Automatically which is always set, and the StartMode which should be set to AlwaysRunning. Both have to be set - the Start Automatically flag is set true by default and controls the starting of the application pool itself while Always Running flag is required in order to launch the application. Without the latter flag set the site settings have no effect.Now on the Site/Application level you can specify whether the site should pre load: Set the Preload Enabled flag to true.At this point ASP.NET apps should auto-load. This is all that's needed to pre-load the site if all you want is to get your site launched automatically.If you want a little more control over the load process you can add a few more settings to your web.config file that allow you to show a static page while the App is starting up. This can be useful if startup is really slow, so rather than displaying blank screen while the user is fiddling their thumbs you can display a static HTML page instead: <system.webServer> <applicationInitialization remapManagedRequestsTo="Startup.htm" skipManagedModules="true"> <add initializationPage="ping.ashx" /> </applicationInitialization> </system.webServer>This allows you to specify a page to execute in a dry run. IIS basically fakes request and pushes it directly into the IIS pipeline without hitting the network. You specify a page and IIS will fake a request to that page in this case ping.ashx which just returns a simple OK string - ie. a fast pipeline request. This request is run immediately after Application Pool restart, and while this request is running and your app is warming up, IIS can display an alternate static page - Startup.htm above. So instead of showing users an empty loading page when clicking a link on your site you can optionally show some sort of static status page that says, "we'll be right back".  I'm not sure if that's such a brilliant idea since this can be pretty disruptive in some cases. Personally I think I prefer letting people wait, but at least get the response they were supposed to get back rather than a random page. But it's there if you need it.Note that the web.config stuff is optional. If you don't provide it IIS hits the default site link (/) and even if there's no matching request at the end of that request it'll still fire the request through the IIS pipeline. Ideally though you want to make sure that an ASP.NET endpoint is hit either with your default page, or by specify the initializationPage to ensure ASP.NET actually gets hit since it's possible for IIS fire unmanaged requests only for static pages (depending how your pipeline is configured).What about AppDomain Restarts?In addition to full Worker Process recycles at the IIS level, ASP.NET also has to deal with AppDomain shutdowns which can occur for a variety of reasons:Files are updated in the BIN folderWeb Deploy to your siteweb.config is changedHard application crashThese operations don't cause the worker process to restart, but they do cause ASP.NET to unload the current AppDomain and start up a new one. Because the features above only apply to Application Pool restarts, AppDomain restarts could also cause your 'ASP.NET service' to stop processing in the background.In order to keep the app running on AppDomain recycles, you can resort to a simple ping in the Application_End event:protected void Application_End() { var client = new WebClient(); var url = App.AdminConfiguration.MonitorHostUrl + "ping.aspx"; client.DownloadString(url); Trace.WriteLine("Application Shut Down Ping: " + url); }which fires any ASP.NET url to the current site at the very end of the pipeline shutdown which in turn ensures that the site immediately starts back up.Manual Configuration in ApplicationHost.configThe above UI corresponds to the following ApplicationHost.config settings. If you're using IIS 7, there's no UI for these flags so you'll have to manually edit them.When you install the Application Initialization component into IIS it should auto-configure the module into ApplicationHost.config. Unfortunately for me, with Mr. Murphy in his best form for me, the module registration did not occur and I had to manually add it.<globalModules> <add name="ApplicationInitializationModule" image="%windir%\System32\inetsrv\warmup.dll" /> </globalModules>Most likely you won't need ever need to add this, but if things are not working it's worth to check if the module is actually registered.Next you need to configure the ApplicationPool and the Web site. The following are the two relevant entries in ApplicationHost.config.<system.applicationHost> <applicationPools> <add name="West Wind West Wind Web Connection" autoStart="true" startMode="AlwaysRunning" managedRuntimeVersion="v4.0" managedPipelineMode="Integrated"> <processModel identityType="LocalSystem" setProfileEnvironment="true" /> </add> </applicationPools> <sites> <site name="Default Web Site" id="1"> <application path="/MPress.Workflow.WebQueueMessageManager" applicationPool="West Wind West Wind Web Connection" preloadEnabled="true"> <virtualDirectory path="/" physicalPath="C:\Clients\…" /> </application> </site> </sites> </system.applicationHost>On the Application Pool make sure to set the autoStart and startMode flags to true and AlwaysRunning respectively. On the site make sure to set the preloadEnabled flag to true.And that's all you should need. You can still set the web.config settings described above as well.ASP.NET as a Service?In the particular application I'm working on currently, we have a queue manager that runs as standalone service that polls a database queue and picks out jobs and processes them on several threads. The service can spin up any number of threads and keep these threads alive in the background while IIS is running doing its own thing. These threads are newly created threads, so they sit completely outside of the IIS thread pool. In order for this service to work all it needs is a long running reference that keeps it alive for the life time of the application.In this particular app there are two components that run in the background on their own threads: A scheduler that runs various scheduled tasks and handles things like picking up emails to send out outside of IIS's scope and the QueueManager. Here's what this looks like in global.asax:public class Global : System.Web.HttpApplication { private static ApplicationScheduler scheduler; private static ServiceLauncher launcher; protected void Application_Start(object sender, EventArgs e) { // Pings the service and ensures it stays alive scheduler = new ApplicationScheduler() { CheckFrequency = 600000 }; scheduler.Start(); launcher = new ServiceLauncher(); launcher.Start(); // register so shutdown is controlled HostingEnvironment.RegisterObject(launcher); }}By keeping these objects around as static instances that are set only once on startup, they survive the lifetime of the application. The code in these classes is essentially unchanged from the Windows Service code except that I could remove the various overrides required for the Windows Service interface (OnStart,OnStop,OnResume etc.). Otherwise the behavior and operation is very similar.In this application ASP.NET serves two purposes: It acts as the host for SignalR and provides the administration interface which allows remote management of the 'service'. I can start and stop the service remotely by shutting down the ApplicationScheduler very easily. I can also very easily feed stats from the queue out directly via a couple of Web requests or (as we do now) through the SignalR service.Registering a Background Object with ASP.NETNotice also the use of the HostingEnvironment.RegisterObject(). This function registers an object with ASP.NET to let it know that it's a background task that should be notified if the AppDomain shuts down. RegisterObject() requires an interface with a Stop() method that's fired and allows your code to respond to a shutdown request. Here's what the IRegisteredObject::Stop() method looks like on the launcher:public void Stop(bool immediate = false) { LogManager.Current.LogInfo("QueueManager Controller Stopped."); Controller.StopProcessing(); Controller.Dispose(); Thread.Sleep(1500); // give background threads some time HostingEnvironment.UnregisterObject(this); }Implementing IRegisterObject should help with reliability on AppDomain shutdowns. Thanks to Justin Van Patten for pointing this out to me on Twitter.RegisterObject() is not required but I would highly recommend implementing it on whatever object controls your background processing to all clean shutdowns when the AppDomain shuts down.Testing it outI'm still in the testing phase with this particular service to see if there are any side effects. But so far it doesn't look like it. With about 50 lines of code I was able to replace the Windows service startup to Web start up - everything else just worked as is. An honorable mention goes to SignalR 2.0's oWin hosting, because with the new oWin based hosting no code changes at all were required, merely a couple of configuration file settings and an assembly directive needed, to point at the SignalR startup class. Sweet!It also seems like SignalR is noticeably faster running inside of IIS compared to self-host. Startup feels faster because of the preload.Starting and Stopping the 'Service'Because the application is running as a Web Server, it's easy to have a Web interface for starting and stopping the services running inside of the service. For our queue manager the SignalR service and front monitoring app has a play and stop button for toggling the queue.If you want more administrative control and have it work more like a Windows Service you can also stop the application pool explicitly from the command line which would be equivalent to stopping and restarting a service.To start and stop from the command line you can use the IIS appCmd tool. To stop:> %windir%\system32\inetsrv\appcmd stop apppool /apppool.name:"Weblog"and to start> %windir%\system32\inetsrv\appcmd start apppool /apppool.name:"Weblog"Note that when you explicitly force the AppPool to stop running either in the UI (on the ApplicationPools page use Start/Stop) or via command line tools, the application pool will not auto-restart immediately. You have to manually start it back up.What's not to like?There are certainly a lot of benefits to running a background service in IIS, but… ASP.NET applications do have more overhead in terms of memory footprint and startup time is a little slower, but generally for server applications this is not a big deal. If the application is stable the service should fire up and stay running indefinitely. A lot of times this kind of service interface can simply be attached to an existing Web application, or if scalability requires be offloaded to its own Web server.Easier to work withBut the ultimate benefit here is that it's much easier to work with a Web app as opposed to a service. While developing I can simply turn off the auto-launch features and launch the service on demand through IIS simply by hitting a page on the site. If I want to shut down an IISRESET -stop will shut down the service easily enough. I can then attach a debugger anywhere I want and this works like any other ASP.NET application. Yes you end up on a background thread for debugging but Visual Studio handles that just fine and if you stay on a single thread this is no different than debugging any other code.SummaryUsing ASP.NET to run background service operations is probably not a super common scenario, but it probably should be something that is considered carefully when building services. Many applications have service like features and with the auto-start functionality of the Application Initialization module, it's easy to build this functionality into ASP.NET. Especially when combined with the notification features of SignalR it becomes very, very easy to create rich services that can also communicate their status easily to the outside world.Whether it's existing applications that need some background processing for scheduling related tasks, or whether you just create a separate site altogether just to host your service it's easy to do and you can leverage the same tool chain you're already using for other Web projects. If you have lots of service projects it's worth considering… give it some thought…© Rick Strahl, West Wind Technologies, 2005-2013Posted in ASP.NET  SignalR  IIS   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • SQL SERVER – Securing TRUNCATE Permissions in SQL Server

    - by pinaldave
    Download the Script of this article from here. On December 11, 2010, Vinod Kumar, a Databases & BI technology evangelist from Microsoft Corporation, graced Ahmedabad by spending some time with the Community during the Community Tech Days (CTD) event. As he was running through a few demos, Vinod asked the audience one of the most fundamental and common interview questions – “What is the difference between a DELETE and TRUNCATE?“ Ahmedabad SQL Server User Group Expert Nakul Vachhrajani has come up with excellent solutions of the same. I must congratulate Nakul for this excellent solution and as a encouragement to User Group member, I am publishing the same article over here. Nakul Vachhrajani is a Software Specialist and systems development professional with Patni Computer Systems Limited. He has functional experience spanning legacy code deprecation, system design, documentation, development, implementation, testing, maintenance and support of complex systems, providing business intelligence solutions, database administration, performance tuning, optimization, product management, release engineering, process definition and implementation. He has comprehensive grasp on Database Administration, Development and Implementation with MS SQL Server and C, C++, Visual C++/C#. He has about 6 years of total experience in information technology. Nakul is an member of the Ahmedabad and Gandhinagar SQL Server User Groups, and actively contributes to the community by actively participating in multiple forums and websites like SQLAuthority.com, BeyondRelational.com, SQLServerCentral.com and many others. Please note: The opinions expressed herein are Nakul own personal opinions and do not represent his employer’s view in anyway. All data from everywhere here on Earth go through a series of  four distinct operations, identified by the words: CREATE, READ, UPDATE and DELETE, or simply, CRUD. Putting in Microsoft SQL Server terms, is the process goes like this: INSERT, SELECT, UPDATE and DELETE/TRUNCATE. Quite a few interesting responses were received and evaluated live during the session. To summarize them, the most important similarity that came out was that both DELETE and TRUNCATE participate in transactions. The major differences (not all) that came out of the exercise were: DELETE: DELETE supports a WHERE clause DELETE removes rows from a table, row-by-row Because DELETE moves row-by-row, it acquires a row-level lock Depending upon the recovery model of the database, DELETE is a fully-logged operation. Because DELETE moves row-by-row, it can fire off triggers TRUNCATE: TRUNCATE does not support a WHERE clause TRUNCATE works by directly removing the individual data pages of a table TRUNCATE directly occupies a table-level lock. (Because a lock is acquired, and because TRUNCATE can also participate in a transaction, it has to be a logged operation) TRUNCATE is, therefore, a minimally-logged operation; again, this depends upon the recovery model of the database Triggers are not fired when TRUNCATE is used (because individual row deletions are not logged) Finally, Vinod popped the big homework question that must be critically analyzed: “We know that we can restrict a DELETE operation to a particular user, but how can we restrict the TRUNCATE operation to a particular user?” After returning home and having a nice cup of coffee, I noticed that my gray cells immediately started to work. Below was the result of my research. As what is always said, the devil is in the details. Upon looking at the Permissions section for the TRUNCATE statement in Books On Line, the following jumps right out: “The minimum permission required is ALTER on table_name. TRUNCATE TABLE permissions default to the table owner, members of the sysadmin fixed server role, and the db_owner and db_ddladmin fixed database roles, and are not transferable. However, you can incorporate the TRUNCATE TABLE statement within a module, such as a stored procedure, and grant appropriate permissions to the module using the EXECUTE AS clause.“ Now, what does this mean? Unlike DELETE, one cannot directly assign permissions to a user/set of users allowing or revoking TRUNCATE rights. However, there is a way to circumvent this. It is important to recall that in Microsoft SQL Server, database engine security surrounds the concept of a “securable”, which is any object like a table, stored procedure, trigger, etc. Rights are assigned to a principal on a securable. Refer to the image below (taken from the SQL Server Books On Line). urable”, which is any object like a table, stored procedure, trigger, etc. Rights are assigned to a principal on a securable. Refer to the image below (taken from the SQL Server Books On Line). SETTING UP THE ENVIRONMENT – (01A_Truncate Table Permissions.sql) Script Provided at the end of the article. By the end of this demo, one will be able to do all the CRUD operations, except the TRUNCATE, and the other will only be able to execute the TRUNCATE. All you will need for this test is any edition of SQL Server 2008. (With minor changes, these scripts can be made to work with SQL 2005.) We begin by creating the following: 1.       A test database 2.        Two database roles: associated logins and users 3.       Switch over to the test database and create a test table. Then, add some data into it. I am using row constructors, which is new to SQL 2008. Creating the modules that will be used to enforce permissions 1.       We have already created one of the modules that we will be assigning permissions to. That module is the table: TruncatePermissionsTest 2.       We will now create two stored procedures; one is for the DELETE operation and the other for the TRUNCATE operation. Please note that for all practical purposes, the end result is the same – all data from the table TruncatePermissionsTest is removed Assigning the permissions Now comes the most important part of the demonstration – assigning permissions. A permissions matrix can be worked out as under: To apply the security rights, we use the GRANT and DENY clauses, as under: That’s it! We are now ready for our big test! THE TEST (01B_Truncate Table Test Queries.sql) Script Provided at the end of the article. I will now need two separate SSMS connections, one with the login AllowedTruncate and the other with the login RestrictedTruncate. Running the test is simple; all that’s required is to run through the script – 01B_Truncate Table Test Queries.sql. What I will demonstrate here via screen-shots is the behavior of SQL Server when logged in as the AllowedTruncate user. There are a few other combinations than what are highlighted here. I will leave the reader the right to explore the behavior of the RestrictedTruncate user and these additional scenarios, as a form of self-study. 1.       Testing SELECT permissions 2.       Testing TRUNCATE permissions (Remember, “deny by default”?) 3.       Trying to circumvent security by trying to TRUNCATE the table using the stored procedure Hence, we have now proved that a user can indeed be assigned permissions to specifically assign TRUNCATE permissions. I also hope that the above has sparked curiosity towards putting some security around the probably “destructive” operations of DELETE and TRUNCATE. I would like to wish each and every one of the readers a very happy and secure time with Microsoft SQL Server. (Please find the scripts – 01A_Truncate Table Permissions.sql and 01B_Truncate Table Test Queries.sql that have been used in this demonstration. Please note that these scripts contain purely test-level code only. These scripts must not, at any cost, be used in the reader’s production environments). 01A_Truncate Table Permissions.sql /* ***************************************************************************************************************** Developed By          : Nakul Vachhrajani Functionality         : This demo is focused on how to allow only TRUNCATE permissions to a particular user How to Use            : 1. Run through, step-by-step through the sequence till Step 08 to create a test database 2. Switch over to the "Truncate Table Test Queries.sql" and execute it step-by-step in two different SSMS windows, one where you have logged in as 'RestrictedTruncate', and the other as 'AllowedTruncate' 3. Come back to "Truncate Table Permissions.sql" 4. Execute Step 10 to cleanup! Modifications         : December 13, 2010 - NAV - Updated to add a security matrix and improve code readability when applying security December 12, 2010 - NAV - Created ***************************************************************************************************************** */ -- Step 01: Create a new test database CREATE DATABASE TruncateTestDB GO USE TruncateTestDB GO -- Step 02: Add roles and users to demonstrate the security of the Truncate operation -- 2a. Create the new roles CREATE ROLE AllowedTruncateRole; GO CREATE ROLE RestrictedTruncateRole; GO -- 2b. Create new logins CREATE LOGIN AllowedTruncate WITH PASSWORD = 'truncate@2010', CHECK_POLICY = ON GO CREATE LOGIN RestrictedTruncate WITH PASSWORD = 'truncate@2010', CHECK_POLICY = ON GO -- 2c. Create new Users using the roles and logins created aboave CREATE USER TruncateUser FOR LOGIN AllowedTruncate WITH DEFAULT_SCHEMA = dbo GO CREATE USER NoTruncateUser FOR LOGIN RestrictedTruncate WITH DEFAULT_SCHEMA = dbo GO -- 2d. Add the newly created login to the newly created role sp_addrolemember 'AllowedTruncateRole','TruncateUser' GO sp_addrolemember 'RestrictedTruncateRole','NoTruncateUser' GO -- Step 03: Change over to the test database USE TruncateTestDB GO -- Step 04: Create a test table within the test databse CREATE TABLE TruncatePermissionsTest (Id INT IDENTITY(1,1), Name NVARCHAR(50)) GO -- Step 05: Populate the required data INSERT INTO TruncatePermissionsTest VALUES (N'Delhi'), (N'Mumbai'), (N'Ahmedabad') GO -- Step 06: Encapsulate the DELETE within another module CREATE PROCEDURE proc_DeleteMyTable WITH EXECUTE AS SELF AS DELETE FROM TruncateTestDB..TruncatePermissionsTest GO -- Step 07: Encapsulate the TRUNCATE within another module CREATE PROCEDURE proc_TruncateMyTable WITH EXECUTE AS SELF AS TRUNCATE TABLE TruncateTestDB..TruncatePermissionsTest GO -- Step 08: Apply Security /* *****************************SECURITY MATRIX*************************************** =================================================================================== Object                   | Permissions |                 Login |             | AllowedTruncate   |   RestrictedTruncate |             |User:NoTruncateUser|   User:TruncateUser =================================================================================== TruncatePermissionsTest  | SELECT,     |      GRANT        |      (Default) | INSERT,     |                   | | UPDATE,     |                   | | DELETE      |                   | -------------------------+-------------+-------------------+----------------------- TruncatePermissionsTest  | ALTER       |      DENY         |      (Default) -------------------------+-------------+----*/----------------+----------------------- proc_DeleteMyTable | EXECUTE | GRANT | DENY -------------------------+-------------+-------------------+----------------------- proc_TruncateMyTable | EXECUTE | DENY | GRANT -------------------------+-------------+-------------------+----------------------- *****************************SECURITY MATRIX*************************************** */ /* Table: TruncatePermissionsTest*/ GRANT SELECT, INSERT, UPDATE, DELETE ON TruncateTestDB..TruncatePermissionsTest TO NoTruncateUser GO DENY ALTER ON TruncateTestDB..TruncatePermissionsTest TO NoTruncateUser GO /* Procedure: proc_DeleteMyTable*/ GRANT EXECUTE ON TruncateTestDB..proc_DeleteMyTable TO NoTruncateUser GO DENY EXECUTE ON TruncateTestDB..proc_DeleteMyTable TO TruncateUser GO /* Procedure: proc_TruncateMyTable*/ DENY EXECUTE ON TruncateTestDB..proc_TruncateMyTable TO NoTruncateUser GO GRANT EXECUTE ON TruncateTestDB..proc_TruncateMyTable TO TruncateUser GO -- Step 09: Test --Switch over to the "Truncate Table Test Queries.sql" and execute it step-by-step in two different SSMS windows: --    1. one where you have logged in as 'RestrictedTruncate', and --    2. the other as 'AllowedTruncate' -- Step 10: Cleanup sp_droprolemember 'AllowedTruncateRole','TruncateUser' GO sp_droprolemember 'RestrictedTruncateRole','NoTruncateUser' GO DROP USER TruncateUser GO DROP USER NoTruncateUser GO DROP LOGIN AllowedTruncate GO DROP LOGIN RestrictedTruncate GO DROP ROLE AllowedTruncateRole GO DROP ROLE RestrictedTruncateRole GO USE MASTER GO DROP DATABASE TruncateTestDB GO 01B_Truncate Table Test Queries.sql /* ***************************************************************************************************************** Developed By          : Nakul Vachhrajani Functionality         : This demo is focused on how to allow only TRUNCATE permissions to a particular user How to Use            : 1. Switch over to this from "Truncate Table Permissions.sql", Step #09 2. Execute this step-by-step in two different SSMS windows a. One where you have logged in as 'RestrictedTruncate', and b. The other as 'AllowedTruncate' 3. Return back to "Truncate Table Permissions.sql" 4. Execute Step 10 to cleanup! Modifications         : December 12, 2010 - NAV - Created ***************************************************************************************************************** */ -- Step 09A: Switch to the test database USE TruncateTestDB GO -- Step 09B: Ensure that we have valid data SELECT * FROM TruncatePermissionsTest GO -- (Expected: Following error will occur if logged in as "AllowedTruncate") -- Msg 229, Level 14, State 5, Line 1 -- The SELECT permission was denied on the object 'TruncatePermissionsTest', database 'TruncateTestDB', schema 'dbo'. --Step 09C: Attempt to Truncate Data from the table without using the stored procedure TRUNCATE TABLE TruncatePermissionsTest GO -- (Expected: Following error will occur) --  Msg 1088, Level 16, State 7, Line 2 --  Cannot find the object "TruncatePermissionsTest" because it does not exist or you do not have permissions. -- Step 09D:Regenerate Test Data INSERT INTO TruncatePermissionsTest VALUES (N'London'), (N'Paris'), (N'Berlin') GO -- (Expected: Following error will occur if logged in as "AllowedTruncate") -- Msg 229, Level 14, State 5, Line 1 -- The INSERT permission was denied on the object 'TruncatePermissionsTest', database 'TruncateTestDB', schema 'dbo'. --Step 09E: Attempt to Truncate Data from the table using the stored procedure EXEC proc_TruncateMyTable GO -- (Expected: Will execute successfully with 'AllowedTruncate' user, will error out as under with 'RestrictedTruncate') -- Msg 229, Level 14, State 5, Procedure proc_TruncateMyTable, Line 1 -- The EXECUTE permission was denied on the object 'proc_TruncateMyTable', database 'TruncateTestDB', schema 'dbo'. -- Step 09F:Regenerate Test Data INSERT INTO TruncatePermissionsTest VALUES (N'Madrid'), (N'Rome'), (N'Athens') GO --Step 09G: Attempt to Delete Data from the table without using the stored procedure DELETE FROM TruncatePermissionsTest GO -- (Expected: Following error will occur if logged in as "AllowedTruncate") -- Msg 229, Level 14, State 5, Line 2 -- The DELETE permission was denied on the object 'TruncatePermissionsTest', database 'TruncateTestDB', schema 'dbo'. -- Step 09H:Regenerate Test Data INSERT INTO TruncatePermissionsTest VALUES (N'Spain'), (N'Italy'), (N'Greece') GO --Step 09I: Attempt to Delete Data from the table using the stored procedure EXEC proc_DeleteMyTable GO -- (Expected: Following error will occur if logged in as "AllowedTruncate") -- Msg 229, Level 14, State 5, Procedure proc_DeleteMyTable, Line 1 -- The EXECUTE permission was denied on the object 'proc_DeleteMyTable', database 'TruncateTestDB', schema 'dbo'. --Step 09J: Close this SSMS window and return back to "Truncate Table Permissions.sql" Thank you Nakul to take up the challenge and prove that Ahmedabad and Gandhinagar SQL Server User Group has talent to solve difficult problems. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Pinal Dave, Readers Contribution, Readers Question, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Security, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Announcing the Release of Visual Studio 2013 and Great Improvements to ASP.NET and Entity Framework

    - by ScottGu
    Today we released VS 2013 and .NET 4.5.1. These releases include a ton of great improvements, and include some fantastic enhancements to ASP.NET and the Entity Framework.  You can download and start using them now. Below are details on a few of the great ASP.NET, Web Development, and Entity Framework improvements you can take advantage of with this release.  Please visit http://www.asp.net/vnext for additional release notes, documentation, and tutorials. One ASP.NET With the release of Visual Studio 2013, we have taken a step towards unifying the experience of using the different ASP.NET sub-frameworks (Web Forms, MVC, Web API, SignalR, etc), and you can now easily mix and match the different ASP.NET technologies you want to use within a single application. When you do a File-New Project with VS 2013 you’ll now see a single ASP.NET Project option: Selecting this project will bring up an additional dialog that allows you to start with a base project template, and then optionally add/remove the technologies you want to use in it.  For example, you could start with a Web Forms template and add Web API or Web Forms support for it, or create a MVC project and also enable Web Forms pages within it: This makes it easy for you to use any ASP.NET technology you want within your apps, and take advantage of any feature across the entire ASP.NET technology span. Richer Authentication Support The new “One ASP.NET” project dialog also includes a new Change Authentication button that, when pushed, enables you to easily change the authentication approach used by your applications – and makes it much easier to build secure applications that enable SSO from a variety of identity providers.  For example, when you start with the ASP.NET Web Forms or MVC templates you can easily add any of the following authentication options to the application: No Authentication Individual User Accounts (Single Sign-On support with FaceBook, Twitter, Google, and Microsoft ID – or Forms Auth with ASP.NET Membership) Organizational Accounts (Single Sign-On support with Windows Azure Active Directory ) Windows Authentication (Active Directory in an intranet application) The Windows Azure Active Directory support is particularly cool.  Last month we updated Windows Azure Active Directory so that developers can now easily create any number of Directories using it (for free and deployed within seconds).  It now takes only a few moments to enable single-sign-on support within your ASP.NET applications against these Windows Azure Active Directories.  Simply choose the “Organizational Accounts” radio button within the Change Authentication dialog and enter the name of your Windows Azure Active Directory to do this: This will automatically configure your ASP.NET application to use Windows Azure Active Directory and register the application with it.  Now when you run the app your users can easily and securely sign-in using their Active Directory credentials within it – regardless of where the application is hosted on the Internet. For more information about the new process for creating web projects, see Creating ASP.NET Web Projects in Visual Studio 2013. Responsive Project Templates with Bootstrap The new default project templates for ASP.NET Web Forms, MVC, Web API and SPA are built using Bootstrap. Bootstrap is an open source CSS framework that helps you build responsive websites which look great on different form factors such as mobile phones, tables and desktops. For example in a browser window the home page created by the MVC template looks like the following: When you resize the browser to a narrow window to see how it would like on a phone, you can notice how the contents gracefully wrap around and the horizontal top menu turns into an icon: When you click the menu-icon above it expands into a vertical menu – which enables a good navigation experience for small screen real-estate devices: We think Bootstrap will enable developers to build web applications that work even better on phones, tablets and other mobile devices – and enable you to easily build applications that can leverage the rich ecosystem of Bootstrap CSS templates already out there.  You can learn more about Bootstrap here. Visual Studio Web Tooling Improvements Visual Studio 2013 includes a new, much richer, HTML editor for Razor files and HTML files in web applications. The new HTML editor provides a single unified schema based on HTML5. It has automatic brace completion, jQuery UI and AngularJS attribute IntelliSense, attribute IntelliSense Grouping, and other great improvements. For example, typing “ng-“ on an HTML element will show the intellisense for AngularJS: This support for AngularJS, Knockout.js, Handlebars and other SPA technologies in this release of ASP.NET and VS 2013 makes it even easier to build rich client web applications: The screen shot below demonstrates how the HTML editor can also now inspect your page at design-time to determine all of the CSS classes that are available. In this case, the auto-completion list contains classes from Bootstrap’s CSS file. No more guessing at which Bootstrap element names you need to use: Visual Studio 2013 also comes with built-in support for both CoffeeScript and LESS editing support. The LESS editor comes with all the cool features from the CSS editor and has specific Intellisense for variables and mixins across all the LESS documents in the @import chain. Browser Link – SignalR channel between browser and Visual Studio The new Browser Link feature in VS 2013 lets you run your app within multiple browsers on your dev machine, connect them to Visual Studio, and simultaneously refresh all of them just by clicking a button in the toolbar. You can connect multiple browsers (including IE, FireFox, Chrome) to your development site, including mobile emulators, and click refresh to refresh all the browsers all at the same time.  This makes it much easier to easily develop/test against multiple browsers in parallel. Browser Link also exposes an API to enable developers to write Browser Link extensions.  By enabling developers to take advantage of the Browser Link API, it becomes possible to create very advanced scenarios that crosses boundaries between Visual Studio and any browser that’s connected to it. Web Essentials takes advantage of the API to create an integrated experience between Visual Studio and the browser’s developer tools, remote controlling mobile emulators and a lot more. You will see us take advantage of this support even more to enable really cool scenarios going forward. ASP.NET Scaffolding ASP.NET Scaffolding is a new code generation framework for ASP.NET Web applications. It makes it easy to add boilerplate code to your project that interacts with a data model. In previous versions of Visual Studio, scaffolding was limited to ASP.NET MVC projects. With Visual Studio 2013, you can now use scaffolding for any ASP.NET project, including Web Forms. When using scaffolding, we ensure that all required dependencies are automatically installed for you in the project. For example, if you start with an ASP.NET Web Forms project and then use scaffolding to add a Web API Controller, the required NuGet packages and references to enable Web API are added to your project automatically.  To do this, just choose the Add->New Scaffold Item context menu: Support for scaffolding async controllers uses the new async features from Entity Framework 6. ASP.NET Identity ASP.NET Identity is a new membership system for ASP.NET applications that we are introducing with this release. ASP.NET Identity makes it easy to integrate user-specific profile data with application data. ASP.NET Identity also allows you to choose the persistence model for user profiles in your application. You can store the data in a SQL Server database or another data store, including NoSQL data stores such as Windows Azure Storage Tables. ASP.NET Identity also supports Claims-based authentication, where the user’s identity is represented as a set of claims from a trusted issuer. Users can login by creating an account on the website using username and password, or they can login using social identity providers (such as Microsoft Account, Twitter, Facebook, Google) or using organizational accounts through Windows Azure Active Directory or Active Directory Federation Services (ADFS). To learn more about how to use ASP.NET Identity visit http://www.asp.net/identity.  ASP.NET Web API 2 ASP.NET Web API 2 has a bunch of great improvements including: Attribute routing ASP.NET Web API now supports attribute routing, thanks to a contribution by Tim McCall, the author of http://attributerouting.net. With attribute routing you can specify your Web API routes by annotating your actions and controllers like this: OAuth 2.0 support The Web API and Single Page Application project templates now support authorization using OAuth 2.0. OAuth 2.0 is a framework for authorizing client access to protected resources. It works for a variety of clients including browsers and mobile devices. OData Improvements ASP.NET Web API also now provides support for OData endpoints and enables support for both ATOM and JSON-light formats. With OData you get support for rich query semantics, paging, $metadata, CRUD operations, and custom actions over any data source. Below are some of the specific enhancements in ASP.NET Web API 2 OData. Support for $select, $expand, $batch, and $value Improved extensibility Type-less support Reuse an existing model OWIN Integration ASP.NET Web API now fully supports OWIN and can be run on any OWIN capable host. With OWIN integration, you can self-host Web API in your own process alongside other OWIN middleware, such as SignalR. For more information, see Use OWIN to Self-Host ASP.NET Web API. More Web API Improvements In addition to the features above there have been a host of other features in ASP.NET Web API, including CORS support Authentication Filters Filter Overrides Improved Unit Testability Portable ASP.NET Web API Client To learn more go to http://www.asp.net/web-api/ ASP.NET SignalR 2 ASP.NET SignalR is library for ASP.NET developers that dramatically simplifies the process of adding real-time web functionality to your applications. Real-time web functionality is the ability to have server-side code push content to connected clients instantly as it becomes available. SignalR 2.0 introduces a ton of great improvements. We’ve added support for Cross-Origin Resource Sharing (CORS) to SignalR 2.0. iOS and Android support for SignalR have also been added using the MonoTouch and MonoDroid components from the Xamarin library (for more information on how to use these additions, see the article Using Xamarin Components from the SignalR wiki). We’ve also added support for the Portable .NET Client in SignalR 2.0 and created a new self-hosting package. This change makes the setup process for SignalR much more consistent between web-hosted and self-hosted SignalR applications. To learn more go to http://www.asp.net/signalr. ASP.NET MVC 5 The ASP.NET MVC project templates integrate seamlessly with the new One ASP.NET experience and enable you to integrate all of the above ASP.NET Web API, SignalR and Identity improvements. You can also customize your MVC project and configure authentication using the One ASP.NET project creation wizard. The MVC templates have also been updated to use ASP.NET Identity and Bootstrap as well. An introductory tutorial to ASP.NET MVC 5 can be found at Getting Started with ASP.NET MVC 5. This release of ASP.NET MVC also supports several nice new MVC-specific features including: Authentication filters: These filters allow you to specify authentication logic per-action, per-controller or globally for all controllers. Attribute Routing: Attribute Routing allows you to define your routes on actions or controllers. To learn more go to http://www.asp.net/mvc Entity Framework 6 Improvements Visual Studio 2013 ships with Entity Framework 6, which bring a lot of great new features to the data access space: Async and Task<T> Support EF6’s new Async Query and Save support enables you to perform asynchronous data access and take advantage of the Task<T> support introduced in .NET 4.5 within data access scenarios.  This allows you to free up threads that might otherwise by blocked on data access requests, and enable them to be used to process other requests whilst you wait for the database engine to process operations. When the database server responds the thread will be re-queued within your ASP.NET application and execution will continue.  This enables you to easily write significantly more scalable server code. Here is an example ASP.NET WebAPI action that makes use of the new EF6 async query methods: Interception and Logging Interception and SQL logging allows you to view – or even change – every command that is sent to the database by Entity Framework. This includes a simple, human readable log – which is great for debugging – as well as some lower level building blocks that give you access to the command and results. Here is an example of wiring up the simple log to Debug in the constructor of an MVC controller: Custom Code-First Conventions The new Custom Code-First Conventions enable bulk configuration of a Code First model – reducing the amount of code you need to write and maintain. Conventions are great when your domain classes don’t match the Code First conventions. For example, the following convention configures all properties that are called ‘Key’ to be the primary key of the entity they belong to. This is different than the default Code First convention that expects Id or <type name>Id. Connection Resiliency The new Connection Resiliency feature in EF6 enables you to register an execution strategy to handle – and potentially retry – failed database operations. This is especially useful when deploying to cloud environments where dropped connections become more common as you traverse load balancers and distributed networks. EF6 includes a built-in execution strategy for SQL Azure that knows about retryable exception types and has some sensible – but overridable – defaults for the number of retries and time between retries when errors occur. Registering it is simple using the new Code-Based Configuration support: These are just some of the new features in EF6. You can visit the release notes section of the Entity Framework site for a complete list of new features. Microsoft OWIN Components Open Web Interface for .NET (OWIN) defines an open abstraction between .NET web servers and web applications, and the ASP.NET “Katana” project brings this abstraction to ASP.NET. OWIN decouples the web application from the server, making web applications host-agnostic. For example, you can host an OWIN-based web application in IIS or self-host it in a custom process. For more information about OWIN and Katana, see What's new in OWIN and Katana. Summary Today’s Visual Studio 2013, ASP.NET and Entity Framework release delivers some fantastic new features that streamline your web development lifecycle. These feature span from server framework to data access to tooling to client-side HTML development.  They also integrate some great open-source technology and contributions from our developer community. Download and start using them today! Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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  • Beware Sneaky Reads with Unique Indexes

    - by Paul White NZ
    A few days ago, Sandra Mueller (twitter | blog) asked a question using twitter’s #sqlhelp hash tag: “Might SQL Server retrieve (out-of-row) LOB data from a table, even if the column isn’t referenced in the query?” Leaving aside trivial cases (like selecting a computed column that does reference the LOB data), one might be tempted to say that no, SQL Server does not read data you haven’t asked for.  In general, that’s quite correct; however there are cases where SQL Server might sneakily retrieve a LOB column… Example Table Here’s a T-SQL script to create that table and populate it with 1,000 rows: CREATE TABLE dbo.LOBtest ( pk INTEGER IDENTITY NOT NULL, some_value INTEGER NULL, lob_data VARCHAR(MAX) NULL, another_column CHAR(5) NULL, CONSTRAINT [PK dbo.LOBtest pk] PRIMARY KEY CLUSTERED (pk ASC) ); GO DECLARE @Data VARCHAR(MAX); SET @Data = REPLICATE(CONVERT(VARCHAR(MAX), 'x'), 65540);   WITH Numbers (n) AS ( SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 0)) FROM master.sys.columns C1, master.sys.columns C2 ) INSERT LOBtest WITH (TABLOCKX) ( some_value, lob_data ) SELECT TOP (1000) N.n, @Data FROM Numbers N WHERE N.n <= 1000; Test 1: A Simple Update Let’s run a query to subtract one from every value in the some_value column: UPDATE dbo.LOBtest WITH (TABLOCKX) SET some_value = some_value - 1; As you might expect, modifying this integer column in 1,000 rows doesn’t take very long, or use many resources.  The STATITICS IO and TIME output shows a total of 9 logical reads, and 25ms elapsed time.  The query plan is also very simple: Looking at the Clustered Index Scan, we can see that SQL Server only retrieves the pk and some_value columns during the scan: The pk column is needed by the Clustered Index Update operator to uniquely identify the row that is being changed.  The some_value column is used by the Compute Scalar to calculate the new value.  (In case you are wondering what the Top operator is for, it is used to enforce SET ROWCOUNT). Test 2: Simple Update with an Index Now let’s create a nonclustered index keyed on the some_value column, with lob_data as an included column: CREATE NONCLUSTERED INDEX [IX dbo.LOBtest some_value (lob_data)] ON dbo.LOBtest (some_value) INCLUDE ( lob_data ) WITH ( FILLFACTOR = 100, MAXDOP = 1, SORT_IN_TEMPDB = ON ); This is not a useful index for our simple update query; imagine that someone else created it for a different purpose.  Let’s run our update query again: UPDATE dbo.LOBtest WITH (TABLOCKX) SET some_value = some_value - 1; We find that it now requires 4,014 logical reads and the elapsed query time has increased to around 100ms.  The extra logical reads (4 per row) are an expected consequence of maintaining the nonclustered index. The query plan is very similar to before (click to enlarge): The Clustered Index Update operator picks up the extra work of maintaining the nonclustered index. The new Compute Scalar operators detect whether the value in the some_value column has actually been changed by the update.  SQL Server may be able to skip maintaining the nonclustered index if the value hasn’t changed (see my previous post on non-updating updates for details).  Our simple query does change the value of some_data in every row, so this optimization doesn’t add any value in this specific case. The output list of columns from the Clustered Index Scan hasn’t changed from the one shown previously: SQL Server still just reads the pk and some_data columns.  Cool. Overall then, adding the nonclustered index hasn’t had any startling effects, and the LOB column data still isn’t being read from the table.  Let’s see what happens if we make the nonclustered index unique. Test 3: Simple Update with a Unique Index Here’s the script to create a new unique index, and drop the old one: CREATE UNIQUE NONCLUSTERED INDEX [UQ dbo.LOBtest some_value (lob_data)] ON dbo.LOBtest (some_value) INCLUDE ( lob_data ) WITH ( FILLFACTOR = 100, MAXDOP = 1, SORT_IN_TEMPDB = ON ); GO DROP INDEX [IX dbo.LOBtest some_value (lob_data)] ON dbo.LOBtest; Remember that SQL Server only enforces uniqueness on index keys (the some_data column).  The lob_data column is simply stored at the leaf-level of the non-clustered index.  With that in mind, we might expect this change to make very little difference.  Let’s see: UPDATE dbo.LOBtest WITH (TABLOCKX) SET some_value = some_value - 1; Whoa!  Now look at the elapsed time and logical reads: Scan count 1, logical reads 2016, physical reads 0, read-ahead reads 0, lob logical reads 36015, lob physical reads 0, lob read-ahead reads 15992.   CPU time = 172 ms, elapsed time = 16172 ms. Even with all the data and index pages in memory, the query took over 16 seconds to update just 1,000 rows, performing over 52,000 LOB logical reads (nearly 16,000 of those using read-ahead). Why on earth is SQL Server reading LOB data in a query that only updates a single integer column? The Query Plan The query plan for test 3 looks a bit more complex than before: In fact, the bottom level is exactly the same as we saw with the non-unique index.  The top level has heaps of new stuff though, which I’ll come to in a moment. You might be expecting to find that the Clustered Index Scan is now reading the lob_data column (for some reason).  After all, we need to explain where all the LOB logical reads are coming from.  Sadly, when we look at the properties of the Clustered Index Scan, we see exactly the same as before: SQL Server is still only reading the pk and some_value columns – so what’s doing the LOB reads? Updates that Sneakily Read Data We have to go as far as the Clustered Index Update operator before we see LOB data in the output list: [Expr1020] is a bit flag added by an earlier Compute Scalar.  It is set true if the some_value column has not been changed (part of the non-updating updates optimization I mentioned earlier). The Clustered Index Update operator adds two new columns: the lob_data column, and some_value_OLD.  The some_value_OLD column, as the name suggests, is the pre-update value of the some_value column.  At this point, the clustered index has already been updated with the new value, but we haven’t touched the nonclustered index yet. An interesting observation here is that the Clustered Index Update operator can read a column into the data flow as part of its update operation.  SQL Server could have read the LOB data as part of the initial Clustered Index Scan, but that would mean carrying the data through all the operations that occur prior to the Clustered Index Update.  The server knows it will have to go back to the clustered index row to update it, so it delays reading the LOB data until then.  Sneaky! Why the LOB Data Is Needed This is all very interesting (I hope), but why is SQL Server reading the LOB data?  For that matter, why does it need to pass the pre-update value of the some_value column out of the Clustered Index Update? The answer relates to the top row of the query plan for test 3.  I’ll reproduce it here for convenience: Notice that this is a wide (per-index) update plan.  SQL Server used a narrow (per-row) update plan in test 2, where the Clustered Index Update took care of maintaining the nonclustered index too.  I’ll talk more about this difference shortly. The Split/Sort/Collapse combination is an optimization, which aims to make per-index update plans more efficient.  It does this by breaking each update into a delete/insert pair, reordering the operations, removing any redundant operations, and finally applying the net effect of all the changes to the nonclustered index. Imagine we had a unique index which currently holds three rows with the values 1, 2, and 3.  If we run a query that adds 1 to each row value, we would end up with values 2, 3, and 4.  The net effect of all the changes is the same as if we simply deleted the value 1, and added a new value 4. By applying net changes, SQL Server can also avoid false unique-key violations.  If we tried to immediately update the value 1 to a 2, it would conflict with the existing value 2 (which would soon be updated to 3 of course) and the query would fail.  You might argue that SQL Server could avoid the uniqueness violation by starting with the highest value (3) and working down.  That’s fine, but it’s not possible to generalize this logic to work with every possible update query. SQL Server has to use a wide update plan if it sees any risk of false uniqueness violations.  It’s worth noting that the logic SQL Server uses to detect whether these violations are possible has definite limits.  As a result, you will often receive a wide update plan, even when you can see that no violations are possible. Another benefit of this optimization is that it includes a sort on the index key as part of its work.  Processing the index changes in index key order promotes sequential I/O against the nonclustered index. A side-effect of all this is that the net changes might include one or more inserts.  In order to insert a new row in the index, SQL Server obviously needs all the columns – the key column and the included LOB column.  This is the reason SQL Server reads the LOB data as part of the Clustered Index Update. In addition, the some_value_OLD column is required by the Split operator (it turns updates into delete/insert pairs).  In order to generate the correct index key delete operation, it needs the old key value. The irony is that in this case the Split/Sort/Collapse optimization is anything but.  Reading all that LOB data is extremely expensive, so it is sad that the current version of SQL Server has no way to avoid it. Finally, for completeness, I should mention that the Filter operator is there to filter out the non-updating updates. Beating the Set-Based Update with a Cursor One situation where SQL Server can see that false unique-key violations aren’t possible is where it can guarantee that only one row is being updated.  Armed with this knowledge, we can write a cursor (or the WHILE-loop equivalent) that updates one row at a time, and so avoids reading the LOB data: SET NOCOUNT ON; SET STATISTICS XML, IO, TIME OFF;   DECLARE @PK INTEGER, @StartTime DATETIME; SET @StartTime = GETUTCDATE();   DECLARE curUpdate CURSOR LOCAL FORWARD_ONLY KEYSET SCROLL_LOCKS FOR SELECT L.pk FROM LOBtest L ORDER BY L.pk ASC;   OPEN curUpdate;   WHILE (1 = 1) BEGIN FETCH NEXT FROM curUpdate INTO @PK;   IF @@FETCH_STATUS = -1 BREAK; IF @@FETCH_STATUS = -2 CONTINUE;   UPDATE dbo.LOBtest SET some_value = some_value - 1 WHERE CURRENT OF curUpdate; END;   CLOSE curUpdate; DEALLOCATE curUpdate;   SELECT DATEDIFF(MILLISECOND, @StartTime, GETUTCDATE()); That completes the update in 1280 milliseconds (remember test 3 took over 16 seconds!) I used the WHERE CURRENT OF syntax there and a KEYSET cursor, just for the fun of it.  One could just as well use a WHERE clause that specified the primary key value instead. Clustered Indexes A clustered index is the ultimate index with included columns: all non-key columns are included columns in a clustered index.  Let’s re-create the test table and data with an updatable primary key, and without any non-clustered indexes: IF OBJECT_ID(N'dbo.LOBtest', N'U') IS NOT NULL DROP TABLE dbo.LOBtest; GO CREATE TABLE dbo.LOBtest ( pk INTEGER NOT NULL, some_value INTEGER NULL, lob_data VARCHAR(MAX) NULL, another_column CHAR(5) NULL, CONSTRAINT [PK dbo.LOBtest pk] PRIMARY KEY CLUSTERED (pk ASC) ); GO DECLARE @Data VARCHAR(MAX); SET @Data = REPLICATE(CONVERT(VARCHAR(MAX), 'x'), 65540);   WITH Numbers (n) AS ( SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 0)) FROM master.sys.columns C1, master.sys.columns C2 ) INSERT LOBtest WITH (TABLOCKX) ( pk, some_value, lob_data ) SELECT TOP (1000) N.n, N.n, @Data FROM Numbers N WHERE N.n <= 1000; Now here’s a query to modify the cluster keys: UPDATE dbo.LOBtest SET pk = pk + 1; The query plan is: As you can see, the Split/Sort/Collapse optimization is present, and we also gain an Eager Table Spool, for Halloween protection.  In addition, SQL Server now has no choice but to read the LOB data in the Clustered Index Scan: The performance is not great, as you might expect (even though there is no non-clustered index to maintain): Table 'LOBtest'. Scan count 1, logical reads 2011, physical reads 0, read-ahead reads 0, lob logical reads 36015, lob physical reads 0, lob read-ahead reads 15992.   Table 'Worktable'. Scan count 1, logical reads 2040, physical reads 0, read-ahead reads 0, lob logical reads 34000, lob physical reads 0, lob read-ahead reads 8000.   SQL Server Execution Times: CPU time = 483 ms, elapsed time = 17884 ms. Notice how the LOB data is read twice: once from the Clustered Index Scan, and again from the work table in tempdb used by the Eager Spool. If you try the same test with a non-unique clustered index (rather than a primary key), you’ll get a much more efficient plan that just passes the cluster key (including uniqueifier) around (no LOB data or other non-key columns): A unique non-clustered index (on a heap) works well too: Both those queries complete in a few tens of milliseconds, with no LOB reads, and just a few thousand logical reads.  (In fact the heap is rather more efficient). There are lots more fun combinations to try that I don’t have space for here. Final Thoughts The behaviour shown in this post is not limited to LOB data by any means.  If the conditions are met, any unique index that has included columns can produce similar behaviour – something to bear in mind when adding large INCLUDE columns to achieve covering queries, perhaps. Paul White Email: [email protected] Twitter: @PaulWhiteNZ

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  • C#/.NET Little Wonders: ConcurrentBag and BlockingCollection

    - by James Michael Hare
    In the first week of concurrent collections, began with a general introduction and discussed the ConcurrentStack<T> and ConcurrentQueue<T>.  The last post discussed the ConcurrentDictionary<T> .  Finally this week, we shall close with a discussion of the ConcurrentBag<T> and BlockingCollection<T>. For more of the "Little Wonders" posts, see C#/.NET Little Wonders: A Redux. Recap As you'll recall from the previous posts, the original collections were object-based containers that accomplished synchronization through a Synchronized member.  With the advent of .NET 2.0, the original collections were succeeded by the generic collections which are fully type-safe, but eschew automatic synchronization.  With .NET 4.0, a new breed of collections was born in the System.Collections.Concurrent namespace.  Of these, the final concurrent collection we will examine is the ConcurrentBag and a very useful wrapper class called the BlockingCollection. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this informative whitepaper by the Microsoft Parallel Computing Platform team here. ConcurrentBag<T> – Thread-safe unordered collection. Unlike the other concurrent collections, the ConcurrentBag<T> has no non-concurrent counterpart in the .NET collections libraries.  Items can be added and removed from a bag just like any other collection, but unlike the other collections, the items are not maintained in any order.  This makes the bag handy for those cases when all you care about is that the data be consumed eventually, without regard for order of consumption or even fairness – that is, it’s possible new items could be consumed before older items given the right circumstances for a period of time. So why would you ever want a container that can be unfair?  Well, to look at it another way, you can use a ConcurrentQueue and get the fairness, but it comes at a cost in that the ordering rules and synchronization required to maintain that ordering can affect scalability a bit.  Thus sometimes the bag is great when you want the fastest way to get the next item to process, and don’t care what item it is or how long its been waiting. The way that the ConcurrentBag works is to take advantage of the new ThreadLocal<T> type (new in System.Threading for .NET 4.0) so that each thread using the bag has a list local to just that thread.  This means that adding or removing to a thread-local list requires very low synchronization.  The problem comes in where a thread goes to consume an item but it’s local list is empty.  In this case the bag performs “work-stealing” where it will rob an item from another thread that has items in its list.  This requires a higher level of synchronization which adds a bit of overhead to the take operation. So, as you can imagine, this makes the ConcurrentBag good for situations where each thread both produces and consumes items from the bag, but it would be less-than-idea in situations where some threads are dedicated producers and the other threads are dedicated consumers because the work-stealing synchronization would outweigh the thread-local optimization for a thread taking its own items. Like the other concurrent collections, there are some curiosities to keep in mind: IsEmpty(), Count, ToArray(), and GetEnumerator() lock collection Each of these needs to take a snapshot of whole bag to determine if empty, thus they tend to be more expensive and cause Add() and Take() operations to block. ToArray() and GetEnumerator() are static snapshots Because it is based on a snapshot, will not show subsequent updates after snapshot. Add() is lightweight Since adding to the thread-local list, there is very little overhead on Add. TryTake() is lightweight if items in thread-local list As long as items are in the thread-local list, TryTake() is very lightweight, much more so than ConcurrentStack() and ConcurrentQueue(), however if the local thread list is empty, it must steal work from another thread, which is more expensive. Remember, a bag is not ideal for all situations, it is mainly ideal for situations where a process consumes an item and either decomposes it into more items to be processed, or handles the item partially and places it back to be processed again until some point when it will complete.  The main point is that the bag works best when each thread both takes and adds items. For example, we could create a totally contrived example where perhaps we want to see the largest power of a number before it crosses a certain threshold.  Yes, obviously we could easily do this with a log function, but bare with me while I use this contrived example for simplicity. So let’s say we have a work function that will take a Tuple out of a bag, this Tuple will contain two ints.  The first int is the original number, and the second int is the last multiple of that number.  So we could load our bag with the initial values (let’s say we want to know the last multiple of each of 2, 3, 5, and 7 under 100. 1: var bag = new ConcurrentBag<Tuple<int, int>> 2: { 3: Tuple.Create(2, 1), 4: Tuple.Create(3, 1), 5: Tuple.Create(5, 1), 6: Tuple.Create(7, 1) 7: }; Then we can create a method that given the bag, will take out an item, apply the multiplier again, 1: public static void FindHighestPowerUnder(ConcurrentBag<Tuple<int,int>> bag, int threshold) 2: { 3: Tuple<int,int> pair; 4:  5: // while there are items to take, this will prefer local first, then steal if no local 6: while (bag.TryTake(out pair)) 7: { 8: // look at next power 9: var result = Math.Pow(pair.Item1, pair.Item2 + 1); 10:  11: if (result < threshold) 12: { 13: // if smaller than threshold bump power by 1 14: bag.Add(Tuple.Create(pair.Item1, pair.Item2 + 1)); 15: } 16: else 17: { 18: // otherwise, we're done 19: Console.WriteLine("Highest power of {0} under {3} is {0}^{1} = {2}.", 20: pair.Item1, pair.Item2, Math.Pow(pair.Item1, pair.Item2), threshold); 21: } 22: } 23: } Now that we have this, we can load up this method as an Action into our Tasks and run it: 1: // create array of tasks, start all, wait for all 2: var tasks = new[] 3: { 4: new Task(() => FindHighestPowerUnder(bag, 100)), 5: new Task(() => FindHighestPowerUnder(bag, 100)), 6: }; 7:  8: Array.ForEach(tasks, t => t.Start()); 9:  10: Task.WaitAll(tasks); Totally contrived, I know, but keep in mind the main point!  When you have a thread or task that operates on an item, and then puts it back for further consumption – or decomposes an item into further sub-items to be processed – you should consider a ConcurrentBag as the thread-local lists will allow for quick processing.  However, if you need ordering or if your processes are dedicated producers or consumers, this collection is not ideal.  As with anything, you should performance test as your mileage will vary depending on your situation! BlockingCollection<T> – A producers & consumers pattern collection The BlockingCollection<T> can be treated like a collection in its own right, but in reality it adds a producers and consumers paradigm to any collection that implements the interface IProducerConsumerCollection<T>.  If you don’t specify one at the time of construction, it will use a ConcurrentQueue<T> as its underlying store. If you don’t want to use the ConcurrentQueue, the ConcurrentStack and ConcurrentBag also implement the interface (though ConcurrentDictionary does not).  In addition, you are of course free to create your own implementation of the interface. So, for those who don’t remember the producers and consumers classical computer-science problem, the gist of it is that you have one (or more) processes that are creating items (producers) and one (or more) processes that are consuming these items (consumers).  Now, the crux of the problem is that there is a bin (queue) where the produced items are placed, and typically that bin has a limited size.  Thus if a producer creates an item, but there is no space to store it, it must wait until an item is consumed.  Also if a consumer goes to consume an item and none exists, it must wait until an item is produced. The BlockingCollection makes it trivial to implement any standard producers/consumers process set by providing that “bin” where the items can be produced into and consumed from with the appropriate blocking operations.  In addition, you can specify whether the bin should have a limited size or can be (theoretically) unbounded, and you can specify timeouts on the blocking operations. As far as your choice of “bin”, for the most part the ConcurrentQueue is the right choice because it is fairly light and maximizes fairness by ordering items so that they are consumed in the same order they are produced.  You can use the concurrent bag or stack, of course, but your ordering would be random-ish in the case of the former and LIFO in the case of the latter. So let’s look at some of the methods of note in BlockingCollection: BoundedCapacity returns capacity of the “bin” If the bin is unbounded, the capacity is int.MaxValue. Count returns an internally-kept count of items This makes it O(1), but if you modify underlying collection directly (not recommended) it is unreliable. CompleteAdding() is used to cut off further adds. This sets IsAddingCompleted and begins to wind down consumers once empty. IsAddingCompleted is true when producers are “done”. Once you are done producing, should complete the add process to alert consumers. IsCompleted is true when producers are “done” and “bin” is empty. Once you mark the producers done, and all items removed, this will be true. Add() is a blocking add to collection. If bin is full, will wait till space frees up Take() is a blocking remove from collection. If bin is empty, will wait until item is produced or adding is completed. GetConsumingEnumerable() is used to iterate and consume items. Unlike the standard enumerator, this one consumes the items instead of iteration. TryAdd() attempts add but does not block completely If adding would block, returns false instead, can specify TimeSpan to wait before stopping. TryTake() attempts to take but does not block completely Like TryAdd(), if taking would block, returns false instead, can specify TimeSpan to wait. Note the use of CompleteAdding() to signal the BlockingCollection that nothing else should be added.  This means that any attempts to TryAdd() or Add() after marked completed will throw an InvalidOperationException.  In addition, once adding is complete you can still continue to TryTake() and Take() until the bin is empty, and then Take() will throw the InvalidOperationException and TryTake() will return false. So let’s create a simple program to try this out.  Let’s say that you have one process that will be producing items, but a slower consumer process that handles them.  This gives us a chance to peek inside what happens when the bin is bounded (by default, the bin is NOT bounded). 1: var bin = new BlockingCollection<int>(5); Now, we create a method to produce items: 1: public static void ProduceItems(BlockingCollection<int> bin, int numToProduce) 2: { 3: for (int i = 0; i < numToProduce; i++) 4: { 5: // try for 10 ms to add an item 6: while (!bin.TryAdd(i, TimeSpan.FromMilliseconds(10))) 7: { 8: Console.WriteLine("Bin is full, retrying..."); 9: } 10: } 11:  12: // once done producing, call CompleteAdding() 13: Console.WriteLine("Adding is completed."); 14: bin.CompleteAdding(); 15: } And one to consume them: 1: public static void ConsumeItems(BlockingCollection<int> bin) 2: { 3: // This will only be true if CompleteAdding() was called AND the bin is empty. 4: while (!bin.IsCompleted) 5: { 6: int item; 7:  8: if (!bin.TryTake(out item, TimeSpan.FromMilliseconds(10))) 9: { 10: Console.WriteLine("Bin is empty, retrying..."); 11: } 12: else 13: { 14: Console.WriteLine("Consuming item {0}.", item); 15: Thread.Sleep(TimeSpan.FromMilliseconds(20)); 16: } 17: } 18: } Then we can fire them off: 1: // create one producer and two consumers 2: var tasks = new[] 3: { 4: new Task(() => ProduceItems(bin, 20)), 5: new Task(() => ConsumeItems(bin)), 6: new Task(() => ConsumeItems(bin)), 7: }; 8:  9: Array.ForEach(tasks, t => t.Start()); 10:  11: Task.WaitAll(tasks); Notice that the producer is faster than the consumer, thus it should be hitting a full bin often and displaying the message after it times out on TryAdd(). 1: Consuming item 0. 2: Consuming item 1. 3: Bin is full, retrying... 4: Bin is full, retrying... 5: Consuming item 3. 6: Consuming item 2. 7: Bin is full, retrying... 8: Consuming item 4. 9: Consuming item 5. 10: Bin is full, retrying... 11: Consuming item 6. 12: Consuming item 7. 13: Bin is full, retrying... 14: Consuming item 8. 15: Consuming item 9. 16: Bin is full, retrying... 17: Consuming item 10. 18: Consuming item 11. 19: Bin is full, retrying... 20: Consuming item 12. 21: Consuming item 13. 22: Bin is full, retrying... 23: Bin is full, retrying... 24: Consuming item 14. 25: Adding is completed. 26: Consuming item 15. 27: Consuming item 16. 28: Consuming item 17. 29: Consuming item 19. 30: Consuming item 18. Also notice that once CompleteAdding() is called and the bin is empty, the IsCompleted property returns true, and the consumers will exit. Summary The ConcurrentBag is an interesting collection that can be used to optimize concurrency scenarios where tasks or threads both produce and consume items.  In this way, it will choose to consume its own work if available, and then steal if not.  However, in situations where you want fair consumption or ordering, or in situations where the producers and consumers are distinct processes, the bag is not optimal. The BlockingCollection is a great wrapper around all of the concurrent queue, stack, and bag that allows you to add producer and consumer semantics easily including waiting when the bin is full or empty. That’s the end of my dive into the concurrent collections.  I’d also strongly recommend, once again, you read this excellent Microsoft white paper that goes into much greater detail on the efficiencies you can gain using these collections judiciously (here). Tweet Technorati Tags: C#,.NET,Concurrent Collections,Little Wonders

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  • What's up with OCFS2?

    - by wcoekaer
    On Linux there are many filesystem choices and even from Oracle we provide a number of filesystems, all with their own advantages and use cases. Customers often confuse ACFS with OCFS or OCFS2 which then causes assumptions to be made such as one replacing the other etc... I thought it would be good to write up a summary of how OCFS2 got to where it is, what we're up to still, how it is different from other options and how this really is a cool native Linux cluster filesystem that we worked on for many years and is still widely used. Work on a cluster filesystem at Oracle started many years ago, in the early 2000's when the Oracle Database Cluster development team wrote a cluster filesystem for Windows that was primarily focused on providing an alternative to raw disk devices and help customers with the deployment of Oracle Real Application Cluster (RAC). Oracle RAC is a cluster technology that lets us make a cluster of Oracle Database servers look like one big database. The RDBMS runs on many nodes and they all work on the same data. It's a Shared Disk database design. There are many advantages doing this but I will not go into detail as that is not the purpose of my write up. Suffice it to say that Oracle RAC expects all the database data to be visible in a consistent, coherent way, across all the nodes in the cluster. To do that, there were/are a few options : 1) use raw disk devices that are shared, through SCSI, FC, or iSCSI 2) use a network filesystem (NFS) 3) use a cluster filesystem(CFS) which basically gives you a filesystem that's coherent across all nodes using shared disks. It is sort of (but not quite) combining option 1 and 2 except that you don't do network access to the files, the files are effectively locally visible as if it was a local filesystem. So OCFS (Oracle Cluster FileSystem) on Windows was born. Since Linux was becoming a very important and popular platform, we decided that we would also make this available on Linux and thus the porting of OCFS/Windows started. The first version of OCFS was really primarily focused on replacing the use of Raw devices with a simple filesystem that lets you create files and provide direct IO to these files to get basically native raw disk performance. The filesystem was not designed to be fully POSIX compliant and it did not have any where near good/decent performance for regular file create/delete/access operations. Cache coherency was easy since it was basically always direct IO down to the disk device and this ensured that any time one issues a write() command it would go directly down to the disk, and not return until the write() was completed. Same for read() any sort of read from a datafile would be a read() operation that went all the way to disk and return. We did not cache any data when it came down to Oracle data files. So while OCFS worked well for that, since it did not have much of a normal filesystem feel, it was not something that could be submitted to the kernel mail list for inclusion into Linux as another native linux filesystem (setting aside the Windows porting code ...) it did its job well, it was very easy to configure, node membership was simple, locking was disk based (so very slow but it existed), you could create regular files and do regular filesystem operations to a certain extend but anything that was not database data file related was just not very useful in general. Logfiles ok, standard filesystem use, not so much. Up to this point, all the work was done, at Oracle, by Oracle developers. Once OCFS (1) was out for a while and there was a lot of use in the database RAC world, many customers wanted to do more and were asking for features that you'd expect in a normal native filesystem, a real "general purposes cluster filesystem". So the team sat down and basically started from scratch to implement what's now known as OCFS2 (Oracle Cluster FileSystem release 2). Some basic criteria were : Design it with a real Distributed Lock Manager and use the network for lock negotiation instead of the disk Make it a Linux native filesystem instead of a native shim layer and a portable core Support standard Posix compliancy and be fully cache coherent with all operations Support all the filesystem features Linux offers (ACL, extended Attributes, quotas, sparse files,...) Be modern, support large files, 32/64bit, journaling, data ordered journaling, endian neutral, we can mount on both endian /cross architecture,.. Needless to say, this was a huge development effort that took many years to complete. A few big milestones happened along the way... OCFS2 was development in the open, we did not have a private tree that we worked on without external code review from the Linux Filesystem maintainers, great folks like Christopher Hellwig reviewed the code regularly to make sure we were not doing anything out of line, we submitted the code for review on lkml a number of times to see if we were getting close for it to be included into the mainline kernel. Using this development model is standard practice for anyone that wants to write code that goes into the kernel and having any chance of doing so without a complete rewrite or.. shall I say flamefest when submitted. It saved us a tremendous amount of time by not having to re-fit code for it to be in a Linus acceptable state. Some other filesystems that were trying to get into the kernel that didn't follow an open development model had a lot harder time and a lot harsher criticism. March 2006, when Linus released 2.6.16, OCFS2 officially became part of the mainline kernel, it was accepted a little earlier in the release candidates but in 2.6.16. OCFS2 became officially part of the mainline Linux kernel tree as one of the many filesystems. It was the first cluster filesystem to make it into the kernel tree. Our hope was that it would then end up getting picked up by the distribution vendors to make it easy for everyone to have access to a CFS. Today the source code for OCFS2 is approximately 85000 lines of code. We made OCFS2 production with full support for customers that ran Oracle database on Linux, no extra or separate support contract needed. OCFS2 1.0.0 started being built for RHEL4 for x86, x86-64, ppc, s390x and ia64. For RHEL5 starting with OCFS2 1.2. SuSE was very interested in high availability and clustering and decided to build and include OCFS2 with SLES9 for their customers and was, next to Oracle, the main contributor to the filesystem for both new features and bug fixes. Source code was always available even prior to inclusion into mainline and as of 2.6.16, source code was just part of a Linux kernel download from kernel.org, which it still is, today. So the latest OCFS2 code is always the upstream mainline Linux kernel. OCFS2 is the cluster filesystem used in Oracle VM 2 and Oracle VM 3 as the virtual disk repository filesystem. Since the filesystem is in the Linux kernel it's released under the GPL v2 The release model has always been that new feature development happened in the mainline kernel and we then built consistent, well tested, snapshots that had versions, 1.2, 1.4, 1.6, 1.8. But these releases were effectively just snapshots in time that were tested for stability and release quality. OCFS2 is very easy to use, there's a simple text file that contains the node information (hostname, node number, cluster name) and a file that contains the cluster heartbeat timeouts. It is very small, and very efficient. As Sunil Mushran wrote in the manual : OCFS2 is an efficient, easily configured, quickly installed, fully integrated and compatible, feature-rich, architecture and endian neutral, cache coherent, ordered data journaling, POSIX-compliant, shared disk cluster file system. Here is a list of some of the important features that are included : Variable Block and Cluster sizes Supports block sizes ranging from 512 bytes to 4 KB and cluster sizes ranging from 4 KB to 1 MB (increments in power of 2). Extent-based Allocations Tracks the allocated space in ranges of clusters making it especially efficient for storing very large files. Optimized Allocations Supports sparse files, inline-data, unwritten extents, hole punching and allocation reservation for higher performance and efficient storage. File Cloning/snapshots REFLINK is a feature which introduces copy-on-write clones of files in a cluster coherent way. Indexed Directories Allows efficient access to millions of objects in a directory. Metadata Checksums Detects silent corruption in inodes and directories. Extended Attributes Supports attaching an unlimited number of name:value pairs to the file system objects like regular files, directories, symbolic links, etc. Advanced Security Supports POSIX ACLs and SELinux in addition to the traditional file access permission model. Quotas Supports user and group quotas. Journaling Supports both ordered and writeback data journaling modes to provide file system consistency in the event of power failure or system crash. Endian and Architecture neutral Supports a cluster of nodes with mixed architectures. Allows concurrent mounts on nodes running 32-bit and 64-bit, little-endian (x86, x86_64, ia64) and big-endian (ppc64) architectures. In-built Cluster-stack with DLM Includes an easy to configure, in-kernel cluster-stack with a distributed lock manager. Buffered, Direct, Asynchronous, Splice and Memory Mapped I/Os Supports all modes of I/Os for maximum flexibility and performance. Comprehensive Tools Support Provides a familiar EXT3-style tool-set that uses similar parameters for ease-of-use. The filesystem was distributed for Linux distributions in separate RPM form and this had to be built for every single kernel errata release or every updated kernel provided by the vendor. We provided builds from Oracle for Oracle Linux and all kernels released by Oracle and for Red Hat Enterprise Linux. SuSE provided the modules directly for every kernel they shipped. With the introduction of the Unbreakable Enterprise Kernel for Oracle Linux and our interest in reducing the overhead of building filesystem modules for every minor release, we decide to make OCFS2 available as part of UEK. There was no more need for separate kernel modules, everything was built-in and a kernel upgrade automatically updated the filesystem, as it should. UEK allowed us to not having to backport new upstream filesystem code into an older kernel version, backporting features into older versions introduces risk and requires extra testing because the code is basically partially rewritten. The UEK model works really well for continuing to provide OCFS2 without that extra overhead. Because the RHEL kernel did not contain OCFS2 as a kernel module (it is in the source tree but it is not built by the vendor in kernel module form) we stopped adding the extra packages to Oracle Linux and its RHEL compatible kernel and for RHEL. Oracle Linux customers/users obviously get OCFS2 included as part of the Unbreakable Enterprise Kernel, SuSE customers get it by SuSE distributed with SLES and Red Hat can decide to distribute OCFS2 to their customers if they chose to as it's just a matter of compiling the module and making it available. OCFS2 today, in the mainline kernel is pretty much feature complete in terms of integration with every filesystem feature Linux offers and it is still actively maintained with Joel Becker being the primary maintainer. Since we use OCFS2 as part of Oracle VM, we continue to look at interesting new functionality to add, REFLINK was a good example, and as such we continue to enhance the filesystem where it makes sense. Bugfixes and any sort of code that goes into the mainline Linux kernel that affects filesystems, automatically also modifies OCFS2 so it's in kernel, actively maintained but not a lot of new development happening at this time. We continue to fully support OCFS2 as part of Oracle Linux and the Unbreakable Enterprise Kernel and other vendors make their own decisions on support as it's really a Linux cluster filesystem now more than something that we provide to customers. It really just is part of Linux like EXT3 or BTRFS etc, the OS distribution vendors decide. Do not confuse OCFS2 with ACFS (ASM cluster Filesystem) also known as Oracle Cloud Filesystem. ACFS is a filesystem that's provided by Oracle on various OS platforms and really integrates into Oracle ASM (Automatic Storage Management). It's a very powerful Cluster Filesystem but it's not distributed as part of the Operating System, it's distributed with the Oracle Database product and installs with and lives inside Oracle ASM. ACFS obviously is fully supported on Linux (Oracle Linux, Red Hat Enterprise Linux) but OCFS2 independently as a native Linux filesystem is also, and continues to also be supported. ACFS is very much tied into the Oracle RDBMS, OCFS2 is just a standard native Linux filesystem with no ties into Oracle products. Customers running the Oracle database and ASM really should consider using ACFS as it also provides storage/clustered volume management. Customers wanting to use a simple, easy to use generic Linux cluster filesystem should consider using OCFS2. To learn more about OCFS2 in detail, you can find good documentation on http://oss.oracle.com/projects/ocfs2 in the Documentation area, or get the latest mainline kernel from http://kernel.org and read the source. One final, unrelated note - since I am not always able to publicly answer or respond to comments, I do not want to selectively publish comments from readers. Sometimes I forget to publish comments, sometime I publish them and sometimes I would publish them but if for some reason I cannot publicly comment on them, it becomes a very one-sided stream. So for now I am going to not publish comments from anyone, to be fair to all sides. You are always welcome to email me and I will do my best to respond to technical questions, questions about strategy or direction are sometimes not possible to answer for obvious reasons.

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  • File Watcher Task

    The task will detect changes to existing files as well as new files, both actions will cause the file to be found when available. A file is available when the task can open it exclusively. This is important for files that take a long time to be written, such as large files, or those that are just written slowly or delivered via a slow network link. It can also be set to look for existing files first (1.2.4.55). The full path of the found file is returned in up to three ways: The ExecValueVariable of the task. This can be set to any String variable. The OutputVariableName when specified. This can be set to any String variable. The FullPath variable within OnFileFoundEvent. This is a File Watcher Task specific event.   Advanced warning of a file having been detected, but not yet available is returned through the OnFileWatcherEvent. This event does not always coincide with the completion of the task, as completion and the OnFileFoundEvent is delayed until the file is ready for use. This event indicates that a file has been detected, and that file will now be monitored until it becomes available. The task will only detect and report on the first file that is created or changes, any subsequent changes will be ignored. Task properties and there usages are documented below: Property Data Type Description Filter String Default filter *.* will watch all files. Standard windows wildcards and patterns can be used to restrict the files monitored. FindExistingFiles Boolean Indicates whether the task should check for any existing files that match the path and filter criteria, before starting the file watcher. IncludeSubdirectories Boolean Indicates whether changes in subdirectories are accepted or ignored. OutputVariableName String The name of the variable into which the full file path found will be written on completion of the task. The variable specified should be of type string. Path String Path to watch for new files or changes to existing files. The path is a directory, not a full filename. For a specific file, enter the file name in the Filter property and the directory in the Path property. PathInputType FileWatcherTask.InputType Three input types are supported for the path: Connection - File connection manager, of type existing folder. Direct Input - Type the path directly into the UI or set on the property as a literal string. Variable – The name of the variable which contains the path. Timeout Integer Time in minutes to wait for a file. If no files are detected within the timeout period the task will fail. The default value of 0 means infinite, and will not expire. TimeoutAsWarning Boolean The default behaviour is to raise an error and fail the task on timeout. This property allows you to suppress the error on timeout, a warning event is raised instead, and the task succeeds. The default value is false.   Installation The task is provided as an MSI file which you can download and run to install it. This simply places the files on disk in the correct locations and also installs the assemblies in the Global Assembly Cache as per Microsoft’s recommendations. You may need to restart the SQL Server Integration Services service, as this caches information about what components are installed, as well as restarting any open instances of Business Intelligence Development Studio (BIDS) / Visual Studio that you may be using to build your SSIS packages. For 2005/2008 Only - Finally you will have to add the task to the Visual Studio toolbox manually. Right-click the toolbox, and select Choose Items.... Select the SSIS Control Flow Items tab, and then check the File Watcher Task in the Choose Toolbox Items window. This process has been described in detail in the related FAQ entry for How do I install a task or transform component? We recommend you follow best practice and apply the current Microsoft SQL Server Service pack to your SQL Server servers and workstations. Downloads The File Watcher Task  is available for SQL Server 2005, SQL Server 2008 (includes R2) and SQL Server 2012. Please choose the version to match your SQL Server version, or you can install multiple versions and use them side by side if you have more than one version of SQL Server installed. File Watcher Task for SQL Server 2005 File Watcher Task for SQL Server 2008 File Watcher Task for SQL Server 2012 Version History SQL Server 2012 Version 3.0.0.16 - SQL Server 2012 release. Includes upgrade support for both 2005 and 2008 packages to 2012. (5 Jun 2012) SQL Server 2008 Version 2.0.0.14 - Fixed user interface bug. A migration problem caused the UI type editors to reference an old SQL 2005 assembly. (17 Nov 2008) Version 2.0.0.7 - SQL Server 2008 release. (20 Oct 2008) SQL Server 2005 Version 1.2.6.100 - Fixed UI bug with TimeoutAsWarning property not saving correctly. Improved expression support in UI. File availability detection changed to use read-only lock, allowing reduced permissions to be used. Corrected installed issue which prevented installation on 64-bit machines with SSIS runtime only components. (18 Mar 2007) Version 1.2.5.73 - Added TimeoutAsWarning property. Gives the ability to suppress the error on timeout, a warning event is raised instead, and the task succeeds. (Task Version 3) (27 Sep 2006) Version 1.2.4.61 - Fixed a bug which could cause a loop condition with an unexpected exception such as incorrect file permissions. (20 Sep 2006) Version 1.2.4.55 - Added FindExistingFiles property. When true the task will check for an existing file before the file watcher itself actually starts. (Task Version 2) (8 Sep 2006) Version 1.2.3.39 - SQL Server 2005 RTM Refresh. SP1 Compatibility Testing. Property type validation improved. (12 Jun 2006) Version 1.2.1.0 - SQL Server 2005 IDW 16 Sept CTP. Futher UI enhancements, including expression indicator. Fixed bug caused by execution within loop Subsequent iterations detected the same file as the first iteration. Added IncludeSubdirectories property. Fixed bug when changes made in subdirectories, and folder change was detected, causing task failure. (Task Version 1) (6 Oct 2005) Version 1.2.0.0 - SQL Server 2005 IDW 15 June CTP. Changes made include an enhanced UI, the PathInputType property for greater flexibility with path input, the OutputVariableName property, and the new OnFileFoundEvent event. (7 Sep 2005) Version 1.1.2 - Public Release (16 Nov 2004) Screenshots   Troubleshooting Make sure you have downloaded the version that matches your version of SQL Server. We offer separate downloads for SQL Server 2005 and SQL Server 2008. If you an error when you try and use the task along the lines of The task with the name "File Watcher Task" and the creation name ... is not registered for use on this computer, this usually indicates that the internal cache of SSIS components needs to be updated. This cache is held by the SSIS service, so you need restart the the SQL Server Integration Services service. You can do this from the Services applet in Control Panel or Administrative Tools in Windows. You can also restart the computer if you prefer. You may also need to restart any current instances of Business Intelligence Development Studio (BIDS) / Visual Studio that you may be using to build your SSIS packages. The full error message is shown below for reference: TITLE: Microsoft Visual Studio ------------------------------ The task with the name "File Watcher Task" and the creation name "Konesans.Dts.Tasks.FileWatcherTask.FileWatcherTask, Konesans.Dts.Tasks.FileWatcherTask, Version=1.2.0.0, Culture=neutral, PublicKeyToken=b2ab4a111192992b" is not registered for use on this computer. Contact Information: File Watcher Task A similar error message can be shown when trying to edit the task if the Microsoft Exception Message Box is not installed. This useful component is installed as part of the SQL Server Management Studio tools but occasionally due to the custom options chosen during SQL Server 2005 setup it may be absent. If you get an error like Could not load file or assembly 'Microsoft.ExceptionMessageBox.. you can manually download and install the missing component. It is available as part of the Feature Pack for SQL Server 2005 release. The feature packs are occasionally updated by Microsoft so you may like to check for a more recent edition, but you can find the Microsoft Exception Message Box download links here - Feature Pack for Microsoft SQL Server 2005 - April 2006 If you encounter this problem on SQL Server 2008, please check that you have installed the SQL Server client components. The component is no longer available as a separate download for SQL Server 2008  as noted in the Microsoft documentation for Deploying an Exception Message Box Application The full error message is shown below for reference, although note that the Version will change between SQL Server 2005 and SQL Server 2008: TITLE: Microsoft Visual Studio ------------------------------ Cannot show the editor for this task. ------------------------------ ADDITIONAL INFORMATION: Could not load file or assembly 'Microsoft.ExceptionMessageBox, Version=9.0.242.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91' or one of its dependencies. The system cannot find the file specified. (Konesans.Dts.Tasks.FileWatcherTask) Once installation is complete you need to manually add the task to the toolbox before you will see it and to be able add it to packages - How do I install a task or transform component? If you are still having issues then contact us, but please provide as much detail as possible about error, as well as which version of the the task you are using and details of the SSIS tools installed. Sample Code If you wanted to use the task programmatically then here is some sample code for creating a basic package and configuring the task. It uses a variable to supply the path to watch, and also sets a variable for the OutputVariableName. Once execution is complete it writes out the file found to the console. /// <summary> /// Create a package with an File Watcher Task /// </summary> public void FileWatcherTaskBasic() { // Create the package Package package = new Package(); package.Name = "FileWatcherTaskBasic"; // Add variable for input path, the folder to look in package.Variables.Add("InputPath", false, "User", @"C:\Temp\"); // Add variable for the file found, to be used on OutputVariableName property package.Variables.Add("FileFound", false, "User", "EMPTY"); // Add the Task package.Executables.Add("Konesans.Dts.Tasks.FileWatcherTask.FileWatcherTask, " + "Konesans.Dts.Tasks.FileWatcherTask, Version=1.2.0.0, Culture=neutral, PublicKeyToken=b2ab4a111192992b"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Set basic properties taskHost.Properties["PathInputType"].SetValue(taskHost, 1); // InputType.Variable taskHost.Properties["Path"].SetValue(taskHost, "User::InputPath"); taskHost.Properties["OutputVariableName"].SetValue(taskHost, "User::FileFound"); #if DEBUG // Save package to disk, DEBUG only new Application().SaveToXml(String.Format(@"C:\Temp\{0}.dtsx", package.Name), package, null); #endif // Display variable value before execution to check EMPTY Console.WriteLine("Result Variable: {0}", package.Variables["User::FileFound"].Value); // Execute package package.Execute(); // Display variable value after execution, e.g. C:\Temp\File.txt Console.WriteLine("Result Variable: {0}", package.Variables["User::FileFound"].Value); // Perform simple check for execution errors if (package.Errors.Count > 0) foreach (DtsError error in package.Errors) { Console.WriteLine("ErrorCode : {0}", error.ErrorCode); Console.WriteLine(" SubComponent : {0}", error.SubComponent); Console.WriteLine(" Description : {0}", error.Description); } else Console.WriteLine("Success - {0}", package.Name); // Clean-up package.Dispose(); } (Updated installation and troubleshooting sections, and added sample code July 2009)

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  • MERGE Bug with Filtered Indexes

    - by Paul White
    A MERGE statement can fail, and incorrectly report a unique key violation when: The target table uses a unique filtered index; and No key column of the filtered index is updated; and A column from the filtering condition is updated; and Transient key violations are possible Example Tables Say we have two tables, one that is the target of a MERGE statement, and another that contains updates to be applied to the target.  The target table contains three columns, an integer primary key, a single character alternate key, and a status code column.  A filtered unique index exists on the alternate key, but is only enforced where the status code is ‘a’: CREATE TABLE #Target ( pk integer NOT NULL, ak character(1) NOT NULL, status_code character(1) NOT NULL,   PRIMARY KEY (pk) );   CREATE UNIQUE INDEX uq1 ON #Target (ak) INCLUDE (status_code) WHERE status_code = 'a'; The changes table contains just an integer primary key (to identify the target row to change) and the new status code: CREATE TABLE #Changes ( pk integer NOT NULL, status_code character(1) NOT NULL,   PRIMARY KEY (pk) ); Sample Data The sample data for the example is: INSERT #Target (pk, ak, status_code) VALUES (1, 'A', 'a'), (2, 'B', 'a'), (3, 'C', 'a'), (4, 'A', 'd');   INSERT #Changes (pk, status_code) VALUES (1, 'd'), (4, 'a');          Target                     Changes +-----------------------+    +------------------+ ¦ pk ¦ ak ¦ status_code ¦    ¦ pk ¦ status_code ¦ ¦----+----+-------------¦    ¦----+-------------¦ ¦  1 ¦ A  ¦ a           ¦    ¦  1 ¦ d           ¦ ¦  2 ¦ B  ¦ a           ¦    ¦  4 ¦ a           ¦ ¦  3 ¦ C  ¦ a           ¦    +------------------+ ¦  4 ¦ A  ¦ d           ¦ +-----------------------+ The target table’s alternate key (ak) column is unique, for rows where status_code = ‘a’.  Applying the changes to the target will change row 1 from status ‘a’ to status ‘d’, and row 4 from status ‘d’ to status ‘a’.  The result of applying all the changes will still satisfy the filtered unique index, because the ‘A’ in row 1 will be deleted from the index and the ‘A’ in row 4 will be added. Merge Test One Let’s now execute a MERGE statement to apply the changes: MERGE #Target AS t USING #Changes AS c ON c.pk = t.pk WHEN MATCHED AND c.status_code <> t.status_code THEN UPDATE SET status_code = c.status_code; The MERGE changes the two target rows as expected.  The updated target table now contains: +-----------------------+ ¦ pk ¦ ak ¦ status_code ¦ ¦----+----+-------------¦ ¦  1 ¦ A  ¦ d           ¦ <—changed from ‘a’ ¦  2 ¦ B  ¦ a           ¦ ¦  3 ¦ C  ¦ a           ¦ ¦  4 ¦ A  ¦ a           ¦ <—changed from ‘d’ +-----------------------+ Merge Test Two Now let’s repopulate the changes table to reverse the updates we just performed: TRUNCATE TABLE #Changes;   INSERT #Changes (pk, status_code) VALUES (1, 'a'), (4, 'd'); This will change row 1 back to status ‘a’ and row 4 back to status ‘d’.  As a reminder, the current state of the tables is:          Target                        Changes +-----------------------+    +------------------+ ¦ pk ¦ ak ¦ status_code ¦    ¦ pk ¦ status_code ¦ ¦----+----+-------------¦    ¦----+-------------¦ ¦  1 ¦ A  ¦ d           ¦    ¦  1 ¦ a           ¦ ¦  2 ¦ B  ¦ a           ¦    ¦  4 ¦ d           ¦ ¦  3 ¦ C  ¦ a           ¦    +------------------+ ¦  4 ¦ A  ¦ a           ¦ +-----------------------+ We execute the same MERGE statement: MERGE #Target AS t USING #Changes AS c ON c.pk = t.pk WHEN MATCHED AND c.status_code <> t.status_code THEN UPDATE SET status_code = c.status_code; However this time we receive the following message: Msg 2601, Level 14, State 1, Line 1 Cannot insert duplicate key row in object 'dbo.#Target' with unique index 'uq1'. The duplicate key value is (A). The statement has been terminated. Applying the changes using UPDATE Let’s now rewrite the MERGE to use UPDATE instead: UPDATE t SET status_code = c.status_code FROM #Target AS t JOIN #Changes AS c ON t.pk = c.pk WHERE c.status_code <> t.status_code; This query succeeds where the MERGE failed.  The two rows are updated as expected: +-----------------------+ ¦ pk ¦ ak ¦ status_code ¦ ¦----+----+-------------¦ ¦  1 ¦ A  ¦ a           ¦ <—changed back to ‘a’ ¦  2 ¦ B  ¦ a           ¦ ¦  3 ¦ C  ¦ a           ¦ ¦  4 ¦ A  ¦ d           ¦ <—changed back to ‘d’ +-----------------------+ What went wrong with the MERGE? In this test, the MERGE query execution happens to apply the changes in the order of the ‘pk’ column. In test one, this was not a problem: row 1 is removed from the unique filtered index by changing status_code from ‘a’ to ‘d’ before row 4 is added.  At no point does the table contain two rows where ak = ‘A’ and status_code = ‘a’. In test two, however, the first change was to change row 1 from status ‘d’ to status ‘a’.  This change means there would be two rows in the filtered unique index where ak = ‘A’ (both row 1 and row 4 meet the index filtering criteria ‘status_code = a’). The storage engine does not allow the query processor to violate a unique key (unless IGNORE_DUP_KEY is ON, but that is a different story, and doesn’t apply to MERGE in any case).  This strict rule applies regardless of the fact that if all changes were applied, there would be no unique key violation (row 4 would eventually be changed from ‘a’ to ‘d’, removing it from the filtered unique index, and resolving the key violation). Why it went wrong The query optimizer usually detects when this sort of temporary uniqueness violation could occur, and builds a plan that avoids the issue.  I wrote about this a couple of years ago in my post Beware Sneaky Reads with Unique Indexes (you can read more about the details on pages 495-497 of Microsoft SQL Server 2008 Internals or in Craig Freedman’s blog post on maintaining unique indexes).  To summarize though, the optimizer introduces Split, Filter, Sort, and Collapse operators into the query plan to: Split each row update into delete followed by an inserts Filter out rows that would not change the index (due to the filter on the index, or a non-updating update) Sort the resulting stream by index key, with deletes before inserts Collapse delete/insert pairs on the same index key back into an update The effect of all this is that only net changes are applied to an index (as one or more insert, update, and/or delete operations).  In this case, the net effect is a single update of the filtered unique index: changing the row for ak = ‘A’ from pk = 4 to pk = 1.  In case that is less than 100% clear, let’s look at the operation in test two again:          Target                     Changes                   Result +-----------------------+    +------------------+    +-----------------------+ ¦ pk ¦ ak ¦ status_code ¦    ¦ pk ¦ status_code ¦    ¦ pk ¦ ak ¦ status_code ¦ ¦----+----+-------------¦    ¦----+-------------¦    ¦----+----+-------------¦ ¦  1 ¦ A  ¦ d           ¦    ¦  1 ¦ d           ¦    ¦  1 ¦ A  ¦ a           ¦ ¦  2 ¦ B  ¦ a           ¦    ¦  4 ¦ a           ¦    ¦  2 ¦ B  ¦ a           ¦ ¦  3 ¦ C  ¦ a           ¦    +------------------+    ¦  3 ¦ C  ¦ a           ¦ ¦  4 ¦ A  ¦ a           ¦                            ¦  4 ¦ A  ¦ d           ¦ +-----------------------+                            +-----------------------+ From the filtered index’s point of view (filtered for status_code = ‘a’ and shown in nonclustered index key order) the overall effect of the query is:   Before           After +---------+    +---------+ ¦ pk ¦ ak ¦    ¦ pk ¦ ak ¦ ¦----+----¦    ¦----+----¦ ¦  4 ¦ A  ¦    ¦  1 ¦ A  ¦ ¦  2 ¦ B  ¦    ¦  2 ¦ B  ¦ ¦  3 ¦ C  ¦    ¦  3 ¦ C  ¦ +---------+    +---------+ The single net change there is a change of pk from 4 to 1 for the nonclustered index entry ak = ‘A’.  This is the magic performed by the split, sort, and collapse.  Notice in particular how the original changes to the index key (on the ‘ak’ column) have been transformed into an update of a non-key column (pk is included in the nonclustered index).  By not updating any nonclustered index keys, we are guaranteed to avoid transient key violations. The Execution Plans The estimated MERGE execution plan that produces the incorrect key-violation error looks like this (click to enlarge in a new window): The successful UPDATE execution plan is (click to enlarge in a new window): The MERGE execution plan is a narrow (per-row) update.  The single Clustered Index Merge operator maintains both the clustered index and the filtered nonclustered index.  The UPDATE plan is a wide (per-index) update.  The clustered index is maintained first, then the Split, Filter, Sort, Collapse sequence is applied before the nonclustered index is separately maintained. There is always a wide update plan for any query that modifies the database. The narrow form is a performance optimization where the number of rows is expected to be relatively small, and is not available for all operations.  One of the operations that should disallow a narrow plan is maintaining a unique index where intermediate key violations could occur. Workarounds The MERGE can be made to work (producing a wide update plan with split, sort, and collapse) by: Adding all columns referenced in the filtered index’s WHERE clause to the index key (INCLUDE is not sufficient); or Executing the query with trace flag 8790 set e.g. OPTION (QUERYTRACEON 8790). Undocumented trace flag 8790 forces a wide update plan for any data-changing query (remember that a wide update plan is always possible).  Either change will produce a successfully-executing wide update plan for the MERGE that failed previously. Conclusion The optimizer fails to spot the possibility of transient unique key violations with MERGE under the conditions listed at the start of this post.  It incorrectly chooses a narrow plan for the MERGE, which cannot provide the protection of a split/sort/collapse sequence for the nonclustered index maintenance. The MERGE plan may fail at execution time depending on the order in which rows are processed, and the distribution of data in the database.  Worse, a previously solid MERGE query may suddenly start to fail unpredictably if a filtered unique index is added to the merge target table at any point. Connect bug filed here Tests performed on SQL Server 2012 SP1 CUI (build 11.0.3321) x64 Developer Edition © 2012 Paul White – All Rights Reserved Twitter: @SQL_Kiwi Email: [email protected]

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  • CodePlex Daily Summary for Friday, June 22, 2012

    CodePlex Daily Summary for Friday, June 22, 2012Popular ReleasesXDA ROM HUB: XDA ROM HUB v0.7: Added custom ROM list. Xperia Active and Arc/s will be added on 0.7.1BlackJumboDog: Ver5.6.5: 2012.06.22 Ver5.6.5  (1) FTP??????? EPSV ?? EPRT ???????PrepareQuery for MVC: PrepareQuery Demo with assemplies: ??????????????? ?????? ?????????? ? ???????? ??????. ????? ?? ?????? ??? ?????? ????????? ????? nuget-??????. Dynamic Linq Query Builder for ASP.NET MVC ??????? ?? Dynamic Linq Query Builder, ? ?????? ??????????? ?????????????. ?????? ???? ??????? ????? ???????????? ? ?????? ?? ????????? ?????????????.DotNetNuke® Form and List: 06.00.01: DotNetNuke Form and List 06.00.01 Changes in 06.00.01 Icons are shown in module action buttons (workaraound to core issue with IconAPI) Fix to Token2XSL Editor, changing List type raised exception MakeTumbnail and ShowXml handlers had been missing in install package Updated help texts for better understanding of filter statement, token support in email subject and css style Major changes for fnL 6.0: DNN 6 Form Patterns including modal PopUps and Tabs http://www.dotnetnuke.com/Po...MVVM Light Toolkit: V4RTM (binaries only) including Windows 8 RP: This package contains all the latest DLLs for MVVM Light V4 RTM. It includes the DLLs for Windows 8 Release Preview. An updated Nuget package is also available at http://nuget.org/packages/MvvmLightLibs An installer with binaries, snippets and templates will follow ASAP.Weapsy - ASP.NET MVC CMS: 1.0.0: - Some changes to Layout and CSS - Changed version number to 1.0.0.0 - Solved Cache and Session items handler error in IIS 7 - Created the Modules, Plugins and Widgets Areas - Replaced CKEditor with TinyMCE - Created the System Info page - Minor changesTabular AMO 2012: Tabular AMO 2012 V2 - release 1.0: This is the first stable release of Tabular AMO 2012 V2. In this download you will find the AMO2Tabular V2 library and the AdventureWorks Tabular AMO 2012 sample project to build a tabular model using the library.AcDown????? - AcDown Downloader Framework: AcDown????? v3.11.7: ?? ●AcDown??????????、??、??????。????,????,?????????????????????????。???????????Acfun、????(Bilibili)、??、??、YouTube、??、???、??????、SF????、????????????。 ●??????AcPlay?????,??????、????????????????。 ● AcDown??????????????????,????????????????????????????。 ● AcDown???????C#??,????.NET Framework 2.0??。?????"Acfun?????"。 ????32??64? Windows XP/Vista/7/8 ??:????????Windows XP???,?????????.NET Framework 2.0???(x86),?????"?????????"??? ??????????????,??????????: ??"AcDown?????"????????? ...NShader - HLSL - GLSL - CG - Shader Syntax Highlighter AddIn for Visual Studio: NShader 1.3 - VS2010 + VS2012: This is a small maintenance release to support new VS2012 as well as VS2010. This release is also fixing the issue The "Comment Selection" include the first line after the selection If the new NShader version doesn't highlight your shader, you can try to: Remove the registry entry: HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\11.0\FontAndColors\Cache Remove all lines using "fx" or "hlsl" in file C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\CommonExtensions\Micr...asp.net membership: v1.0 Membership Management: Abmemunit is a Membership Management Project where developer can use their learning purposes of various issues related to ASP.NET, MVC, ASP.NET membership, Entity Framework, Code First, Ajax, Unit Test, IOC Container, Repository, and Service etc. Though it is a very simple project and all of these topics are used in an easy manner gathering from various big projects, it can easily understand. User End Functional Specification The functionalities of this project are very simple and straight...JSON Toolkit: JSON Toolkit 4.0: Up to 2.5x performance improvement in stringify operations Up to 1.7x performance improvement in parse operations Improved error messages when parsing invalid JSON strings Extended support to .Net 2.0, .Net 3.5, .Net 4.0, Silverlight 4, Windows Phone, Windows 8 metro apps and Xbox JSON namespace changed to ComputerBeacon.Json namespaceXenta Framework - extensible enterprise n-tier application framework: Xenta Framework 1.8.0: System Requirements OS Windows 7 Windows Vista Windows Server 2008 Windows Server 2008 R2 Web Server Internet Information Service 7.0 or above .NET Framework .NET Framework 4.0 WCF Activation feature HTTP Activation Non-HTTP Activation for net.pipe/net.tcp WCF bindings ASP.NET MVC ASP.NET MVC 3.0 Database Microsoft SQL Server 2005 Microsoft SQL Server 2008 Microsoft SQL Server 2008 R2 Additional Deployment Configuration Started Windows Process Activation service Start...CrashReporter.NET : Exception reporting library for C# and VB.NET: CrashReporter.NET 1.1: Added screenshot support that takes screenshot of user's desktop on application crash and provides option to include screenshot with crash report. Added Windows version in crash reports. Added email field and exception type field in crash report dialog. Added exception type in crash reports. Added screenshot tab that shows crash screenshot.MFCMAPI: June 2012 Release: Build: 15.0.0.1034 Full release notes at SGriffin's blog. If you just want to run the MFCMAPI or MrMAPI, get the executables. If you want to debug them, get the symbol files and the source. The 64 bit builds will only work on a machine with Outlook 2010 64 bit installed. All other machines should use the 32 bit builds, regardless of the operating system. Facebook BadgeMonoGame - Write Once, Play Everywhere: MonoGame 2.5.1: Release Notes The MonoGame team are pleased to announce that MonoGame v2.5.1 has been released. This release contains important bug fixes and minor updates. Recent additions include project templates for iOS and MacOS. The MonoDevelop.MonoGame AddIn also works on Linux. We have removed the dependency on the thirdparty GamePad library to allow MonoGame to be included in the debian/ubuntu repositories. There have been a major bug fix to ensure textures are disposed of correctly as well as some ...????: ????2.0.2: 1、???????????。 2、DJ???????10?,?????????10?。 3、??.NET 4.5(Windows 8)????????????。 4、???????????。 5、??????????????。 6、???Windows 8????。 7、?????2.0.1???????????????。 8、??DJ?????????。Azure Storage Explorer: Azure Storage Explorer 5 Preview 1 (6.17.2012): Azure Storage Explorer verison 5 is in development, and Preview 1 provides an early look at the new user interface and some of the new features. Here's what's new in v5 Preview 1: New UI, similar to the new Windows Azure HTML5 portal Support for configuring and viewing storage account logging Support for configuring and viewing storage account monitoring Uses the Windows Azure 1.7 SDK libraries Bug fixes????????API for .Net SDK: SDK for .Net ??? Release 2: 6?20????? ?? - FrindesInActive???????json?????????,???????????。??。 6?19????? ?? - ???????????????,???????0?????????。 ?? - ???Entity?????Suggestion??????????????JSON????????。 ?? - ???OAuth?Request??????AccessToken???SourceKey????QueryString?????????。 6?17????? ??? - .net 4.0 SDK??Dynamic??????????????????API?? ??? - ?Utility?????????API??????DateTime???ParseUTCDate ?? - ?????????????Json.net???,???SDK????Json.net?????。 ?? - ???Client??????API???GetCommand?PostCommand,??????????????...KangaModeling: Kanga Modeling 1.0: This is the public release 1.0 of Kanga Modeling. -Cosmos (C# Open Source Managed Operating System): Release 92560: Prerequisites Visual Studio 2010 - Any version including Express. Express users must also install Visual Studio 2010 Integrated Shell runtime VMWare - Cosmos can run on real hardware as well as other virtualization environments but our default debug setup is configured for VMWare. VMWare Player (Free). or Workstation VMWare VIX API 1.11New ProjectsBilling and Collection .NET (BACS.Net): BACS.NET is a project to create a billing and collections system for financial users in a small, parochial school environment.Bing Wallpaper: Gets current picture from Bing and sets it as wallpaper, with optional correction of aspect ratioBlogForFree: This is a simple blog for free users.Break Time: Break-Time reminds you to take a mental and physical break from sitting in front of your computer for too long. Yes, a glorified timer but better, I promise!BTasks: Sistema para controle de tarefas.Calculate Library: Calculate Library is a library capable of parsing math expressions from strings and evaluating the value at run time. ControleMatricula: Este projeto tem por objetivo realizar o gerenciamento de matriculas de cursos escolares.EagleTrack2012: Application for tracking achievements for scout type programsFury OS: FuryOS isn't reinventing the wheel. Fury is a new simple COSMOS OS written to run on real hardware with a GUI and Dynamite#/D# programming language. Take a lookGeneric Compact Input Language: Generic Compact Input Language (GCIL) is a library supporting interpretation of a customizable input language. hgdd06212012: fdghgdd062120123: asdhgdd062120125: weJava to CSharp: This is a tiny project with an intention to make it large. Currently it can be used to convert very tiny and simple Java programs to C# .ModelStore: This project aims to create a generic engine and persistence store for modeling operations.MsSqlMetaDataProvider: Simple wrapper around system views using entity framework model. Intended to be used for auto code generation and template consumption.Multiple Select Refinement Panel Web Part: Multiple Select Refinement Panel web part is developed by extending the out of the box Refinement Panel. It is built over a TreeView control with all the nodes Note+: Coming SoonPrairieAsunder: PrairieAsunder is an HTML5 + MVC3 application that streams local music from Central Illinois. The code is a fork of the Chavah Messianic Radio codebaseRemoteCommand Add-On Module for Mayhem: RemoteCommand is and add-on module for the CodePlex project Mayhem. RemoteCommand allows remote systems, such as IVR's, to trigger events .Results Per Page Search Core Results Web Part: Results Per Page Search Core Results web part is developed by extending the out of the box Search Core Results web part.Secure Socket Protocol: Create a secured Server/Client the easy way with SSPSkype Screen Saver: A handy addition for those who use Skype and like to use headphones. And for those who are mute speakers - too..Tabular AMO 2012: Tabular AMO 2012 is about creating and managing tabular models using the AMO api. It is a developer’s sample, for those interested in managing Analysis Servicestestdd062120126: sdtesttom06212012git01: gfdgfdgfdXDesigner.Development: .Tools for developer , Support VS.NET , VB6.0 or others, Future: 1.Source code line count . 2.Add or remove comment batch. 3.Copy source file clearly. ......

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  • CodePlex Daily Summary for Friday, January 07, 2011

    CodePlex Daily Summary for Friday, January 07, 2011Popular ReleasesAutoLoL: AutoLoL v1.5.2: Implemented the Auto Updater Fix: Your settings will no longer be cleared with new releases of AutoLoL The mastery Editor and Browser now have their own tabs instead of nested tabs The Browser tab will only show the masteries matching ALL filters instead of just one Added a 'Browse' button in the Mastery Editor tab to open the Masteries Directory The Browser tab now shows a message when there are no mastery files in the Masteries Directory Fix: Fixed the Save As dialog again, for ...Ionics Isapi Rewrite Filter: 2.1 latest stable: V2.1 is stable, and is in maintenance mode. This is v2.1.1.25. It is a bug-fix release. There are no new features. 28629 29172 28722 27626 28074 29164 27659 27900 many documentation updates and fixes proper x64 build environment. This release includes x64 binaries in zip form, but no x64 MSI file. You'll have to manually install x64 servers, following the instructions in the documentation.StyleCop for ReSharper: StyleCop for ReSharper 5.1.14980.000: A considerable amount of work has gone into this release: Huge focus on performance around the violation scanning subsystem: - caching added to reduce IO operations around reading and merging of settings files - caching added to reduce creation of expensive objects Users should notice condsiderable perf boost and a decrease in memory usage. Bug Fixes: - StyleCop's new ObjectBasedEnvironment object does not resolve the StyleCop installation path, thus it does not return the correct path ...VivoSocial: VivoSocial 7.4.1: New release with bug fixes and updates for performance.SSH.NET Library: 2011.1.6: Fixes CommandTimeout default value is fixed to infinite. Port Forwarding feature improvements Memory leaks fixes New Features Add ErrorOccurred event to handle errors that occurred on different thread New and improve SFTP features SftpFile now has more attributes and some operations Most standard operations now available Allow specify encoding for command execution KeyboardInteractiveConnectionInfo class added for "keyboard-interactive" authentication. Add ability to specify bo....NET Extensions - Extension Methods Library for C# and VB.NET: Release 2011.03: Added lot's of new extensions and new projects for MVC and Entity Framework. object.FindTypeByRecursion Int32.InRange String.RemoveAllSpecialCharacters String.IsEmptyOrWhiteSpace String.IsNotEmptyOrWhiteSpace String.IfEmptyOrWhiteSpace String.ToUpperFirstLetter String.GetBytes String.ToTitleCase String.ToPlural DateTime.GetDaysInYear DateTime.GetPeriodOfDay IEnumberable.RemoveAll IEnumberable.Distinct ICollection.RemoveAll IList.Join IList.Match IList.Cast Array.IsNullOrEmpty Array.W...VidCoder: 0.8.0: Added x64 version. Made the audio output preview more detailed and accurate. If the chosen encoder or mixdown is incompatible with the source, the fallback that will be used is displayed. Added "Auto" to the audio mixdown choices. Reworked non-anamorphic size calculation to work better with non-standard pixel aspect ratios and cropping. Reworked Custom anamorphic to be more intuitive and allow display width to be set automatically (Thanks, Statick). Allowing higher bitrates for 6-ch....NET Voice Recorder: Auto-Tune Release: This is the source code and binaries to accompany the article on the Coding 4 Fun website. It is the Auto Tuner release of the .NET Voice Recorder application.BloodSim: BloodSim - 1.3.2.0: - Simulation Log is now automatically disabled and hidden when running 10 or more iterations - Hit and Expertise are now entered by Rating, and include option for a Racial Expertise bonus - Added option for boss to use a periodic magic ability (Dragon Breath) - Added option for boss to periodically Enrage, gaining a Damage/Attack Speed buffASP.NET MVC CMS ( Using CommonLibrary.NET ): CommonLibrary.NET CMS 0.9.5 Alpha: CommonLibrary CMSA simple yet powerful CMS system in ASP.NET MVC 2 using C# 4.0. ActiveRecord based components for Blogs, Widgets, Pages, Parts, Events, Feedback, BlogRolls, Links Includes several widgets ( tag cloud, archives, recent, user cloud, links twitter, blog roll and more ) Built using the http://commonlibrarynet.codeplex.com framework. ( Uses TDD, DDD, Models/Entities, Code Generation ) Can run w/ In-Memory Repositories or Sql Server Database See Documentation tab for Ins...AllNewsManager.NET: AllNewsManager.NET 1.2.1: AllNewsManager.NET 1.2.1 It is a minor update from version 1.2EnhSim: EnhSim 2.2.9 BETA: 2.2.9 BETAThis release supports WoW patch 4.03a at level 85 To use this release, you must have the Microsoft Visual C++ 2010 Redistributable Package installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=A7B7A05E-6DE6-4D3A-A423-37BF0912DB84 To use the GUI you must have the .NET 4.0 Framework installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=9cfb2d51-5ff4-4491-b0e5-b386f32c0992 - Added in the Gobl...xUnit.net - Unit Testing for .NET: xUnit.net 1.7 Beta: xUnit.net release 1.7 betaBuild #1533 Important notes for Resharper users: Resharper support has been moved to the xUnit.net Contrib project. Important note for TestDriven.net users: If you are having issues running xUnit.net tests in TestDriven.net, especially on 64-bit Windows, we strongly recommend you upgrade to TD.NET version 3.0 or later. This release adds the following new features: Added support for ASP.NET MVC 3 Added Assert.Equal(double expected, double actual, int precision)...Json.NET: Json.NET 4.0 Release 1: New feature - Added Windows Phone 7 project New feature - Added dynamic support to LINQ to JSON New feature - Added dynamic support to serializer New feature - Added INotifyCollectionChanged to JContainer in .NET 4 build New feature - Added ReadAsDateTimeOffset to JsonReader New feature - Added ReadAsDecimal to JsonReader New feature - Added covariance to IJEnumerable type parameter New feature - Added XmlSerializer style Specified property support New feature - Added ...DbDocument: DbDoc Initial Version: DbDoc Initial versionASP .NET MVC CMS (Content Management System): Atomic CMS 2.1.2: Atomic CMS 2.1.2 release notes Atomic CMS installation guide N2 CMS: 2.1: N2 is a lightweight CMS framework for ASP.NET. It helps you build great web sites that anyone can update. Major Changes Support for auto-implemented properties ({get;set;}, based on contribution by And Poulsen) All-round improvements and bugfixes File manager improvements (multiple file upload, resize images to fit) New image gallery Infinite scroll paging on news Content templates First time with N2? Try the demo site Download one of the template packs (above) and open the proj...Mobile Device Detection and Redirection: 0.1.11.10: IMPORTANT CHANGESThis release changes the way some WURFL capabilities and attributes are exposed to .NET developers. If you cast MobileCapabilities to return some values then please read the Release Note before implementing this release. The following code snippet can be used to access any WURFL capability. For instance, if the device is a tablet: string capability = Request.Browser["is_tablet"]; SummaryNew attributes have been added to the redirect section: originalUrlAsQueryString If se...Wii Backup Fusion: Wii Backup Fusion 1.0: - Norwegian translation - French translation - German translation - WBFS dump for analysis - Scalable full HQ cover - Support for log file - Load game images improved - Support for image splitting - Diff for images after transfer - Support for scrubbing modes - Search functionality for log - Recurse depth for Files/Load - Show progress while downloading game cover - Supports more databases for cover download - Game cover loading routines improvedBlogEngine.NET: BlogEngine.NET 2.0: Get DotNetBlogEngine for 3 Months Free! Click Here for More Info 3 Months FREE – BlogEngine.NET Hosting – Click Here! If you want to set up and start using BlogEngine.NET right away, you should download the Web project. If you want to extend or modify BlogEngine.NET, you should download the source code. If you are upgrading from a previous version of BlogEngine.NET, please take a look at the Upgrading to BlogEngine.NET 2.0 instructions. To get started, be sure to check out our installatio...New Projects9192631770: This project is created for learning .net 3.5 personally. However it may not suffice for anyone to give a start point. (9192631770) is equivalent to 1 sec in atomic clock.AGS: AGSAll-In-One Code Framework Prerelease: All-In-One Code Framework PrereleaseAwait Events with "yield": This is a library that allows you to stop running the code wherever you want in order to await an event using the functionality of "yield" sentence. It's useful when you want to await asynchronous events or when you have to deal with many events in a sequential way.Battle.net SDK: This is a SDK that retrieves it's information from the Battle.Net community site. At the moment blizzard only supports this for World of Warcraft, so that's what our main aim is at the momeen.t C++ Hash Container Benchmark: C++ Hash Container Benchmark for STL map, C++0x unordered map, Boost unordered map, ATL map and ATL hash map for STL wide string and ATL CString.Colour Lovers .NET: A .NET library for the Colour Lovers API.DatingGame: Course to teach high-school aged girls basic T-SQL using a fun scenario - querying to find the hottest boys! Used at Microsoft DigiGirlz and TKP events. Included DDL script, CSV for bcp with data, PPTX, T-SQL Cheat Sheet and teaching tips. Enjoy!do-Dots open .NET SDK: The do-Dots open SDK brings developers a full set of classes that allow to build applications based on do-Dots, a framework for M2M communication. It's developed in C#. EFMVC - ASP.NET MVC 3 and EF Code First: Demo web app using ASP.NET MVC 3 and EF Code FirstGS1: D is a 2D game demo written in C++ and using an API : HAPI for the graphic part and the audio part. All the xml files are handled with tinyXML. It is a vertical scrolling shoot'em up where the player controls a dragon flying in Central Park.GS2: In Zombies, you are a wizard, the most powerful wizard in the world, and two days ago, the Devil forces began to attack our world. The only person capable of stopping them is you, this is why the Devil himself came to you and took your powers. You're now alone, without any weaponIPProvider: DFGiwtfly: ????iwtfly26050: iwtfly2Knowledge Exchange .Net: This is my learning experience with creating an enterprise scale .NET application with tools such as Tortoise SVN, NANT, and Linq to SQLLinqPad Data Context Driver for SharePoint: The SharePoint Data Context Driver for LinqPad makes it easer for SharePoint 2010 Developers to develop, maintain and just play around with Linq To SharePoint statements via LinqPad. It is developed in C# and enables SharePoint 2010 Support to LinqPad.MaxLeafWebSiteK3: MaxLeafWebSiteK3Open ASP.NET CMS: Open ASP.NET 3.5 CMS Plug 'N Play Settings Manager: Plug 'N Play Settings Manager will be an application to configure settings on a windows computer by waiting for a usb thumbstick with a configuration file to be inserted, the application would then read and apply those settings. The early focus will be applying network settings.project windy: Windy - enhanced window manager. windy does window management a breeze. It started as a windows alternative to divvy, but now it has evolved with into its own. Thanks to the generous feedback from you folks. whats different from divvy? - first - its free. - has divvy likeRiaMVVM : MVVM Friendly WCF Ria Services: Simple, light-weight, MVVM friendly access to WCF Ria Services. Written in C# for use with Silverlight 4.SharePoint Designer 2007 Policy: Enable or Disable SharePoint Designer 2007 per site web application and per site colleciton. Spruckus - SharePoint ReUsable Content Keystamp Usage Search: Adds a keystamp to all html type items in the SharePoint Reusable Content list and adds a context item to the reusable content list that will find usages of that reusable content in your site using search.Student Insiders: Student InsidersTea: Tea Web Operator SystemVegas.NET: Projeto teste de TransportadoraXNA 4 Game state management system: XNA 4 Game State Management??????: aa

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  • Oracle HRMS API – Create Employee

    - by PRajkumar
    API - hr_employee_api.create_employee Example --    -- Create Employee  -- ------------------------- DECLARE    lc_employee_number                       PER_ALL_PEOPLE_F.EMPLOYEE_NUMBER%TYPE    := 'PRAJ_01';  ln_person_id                                      PER_ALL_PEOPLE_F.PERSON_ID%TYPE;  ln_assignment_id                             PER_ALL_ASSIGNMENTS_F.ASSIGNMENT_ID%TYPE;  ln_object_ver_number                     PER_ALL_ASSIGNMENTS_F.OBJECT_VERSION_NUMBER%TYPE;  ln_asg_ovn                                          NUMBER;    ld_per_effective_start_date             PER_ALL_PEOPLE_F.EFFECTIVE_START_DATE%TYPE;  ld_per_effective_end_date              PER_ALL_PEOPLE_F.EFFECTIVE_END_DATE%TYPE;  lc_full_name                                        PER_ALL_PEOPLE_F.FULL_NAME%TYPE;  ln_per_comment_id                          PER_ALL_PEOPLE_F.COMMENT_ID%TYPE;  ln_assignment_sequence                 PER_ALL_ASSIGNMENTS_F.ASSIGNMENT_SEQUENCE%TYPE;  lc_assignment_number                    PER_ALL_ASSIGNMENTS_F.ASSIGNMENT_NUMBER%TYPE;    lb_name_combination_warning   BOOLEAN;  lb_assign_payroll_warning           BOOLEAN;  lb_orig_hire_warning                       BOOLEAN;   BEGIN            hr_employee_api.create_employee            (   -- Input data elements                 -- ------------------------------                p_hire_date                                         => TO_DATE('08-JUN-2011'),                p_business_group_id                      => fnd_profile.value_specific('PER_BUSINESS_GROUP_ID'),                p_last_name                                       => 'TEST',                p_first_name                                       => 'PRAJKUMAR',                p_middle_names                              => NULL,                p_sex                                                     => 'M',                p_national_identifier                       => '183-09-6723',                p_date_of_birth                                 => TO_DATE('03-DEC-1988'),                p_known_as                                       => 'PRAJ',                 -- Output data elements                 -- --------------------------------                p_employee_number                         => lc_employee_number,                p_person_id                                         => ln_person_id,                p_assignment_id                                => ln_assignment_id,                p_per_object_version_number       => ln_object_ver_number,                p_asg_object_version_number       => ln_asg_ovn,                p_per_effective_start_date               => ld_per_effective_start_date,                p_per_effective_end_date                => ld_per_effective_end_date,                p_full_name                                         => lc_full_name,                p_per_comment_id                            => ln_per_comment_id,                p_assignment_sequence                  => ln_assignment_sequence,                p_assignment_number                     => lc_assignment_number,                p_name_combination_warning    => lb_name_combination_warning,                p_assign_payroll_warning            => lb_assign_payroll_warning,                p_orig_hire_warning                        => lb_orig_hire_warning          );       COMMIT;   EXCEPTION       WHEN OTHERS THEN                     ROLLBACK;                     dbms_output.put_line(SQLERRM); END; / SHOW ERR;  

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  • Error Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException [migrated]

    - by user134212
    I'm new here. I'm learning how to program on java and I have a problem with my code. I really have no clue why my code is not working. I think my mistake may be here, but I'm not quite sure. m3 = new Matriz(ren2,col2); btSumar.addActionListener(new ActionListener() { Matriz m3;//(ren2,col2); public void actionPerformed(ActionEvent e) { m3 = new Matriz(ren2,col2); if(ventanaAbierta==true) { try { crearMat.SUMA(m1,m2); } catch(Exception nul) { System.out.println(nul); } } else { JOptionPane.showMessageDialog(null,"Ya se realizo la suma"); } } }); My Complete code import java.awt.*; import javax.swing.*; import javax.swing.BorderFactory; import javax.swing.border.Border; import java.awt.event.*; import java.awt.*; import java.io.*; import java.util.*; public class Practica2 { private int opcion,ren2,col2; private JFrame ventana,ventanaPrintMatriz; private JPanel panel,panel2; private Border borderRed2,borderBlue2,borderGreen2,borderGreen4; private Color red,green,blue,white,black; private Font Verdana14,ArialBlack18; private JLabel labelTitulo; public JButton btSalir,btSumar,btRestar,btMultiplica,btTranspuesta,btCrear; private ImageIcon suma,resta,multi,crear,salir,trans; private boolean ventanaAbierta = false; private static ValidacionesMatrices valida; private static Operaciones operacion; private static Matriz m1,m2,m3; private static ImprimirMatriz printMat; public Practica2() { panel = new JPanel(); panel.setLayout(null); ventana = new JFrame("Operaciones con Matrices"); ventana.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); ventana.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { //Sale del programa System.exit(0); } }); ventana.setContentPane(panel); ventana.setVisible(true); ventana.setResizable(false); ventana.setBounds(150,150,300,380); //ventana.setBounds(0,0,650,650); } public void inicializarComponentes() { panel2 = new JPanel(); panel2.setLayout(null); labelTitulo = new JLabel("Practica #2"); suma = new ImageIcon("suma1.png"); resta = new ImageIcon("resta1.png"); multi = new ImageIcon("multi1.png"); trans = new ImageIcon("trans2.png"); crear = new ImageIcon("crear1.png"); salir = new ImageIcon("salir1.png"); btTranspuesta = new JButton("Transpuesta",trans); btMultiplica = new JButton("Multiplica",multi); btRestar = new JButton("Restar",resta); btSumar = new JButton("Sumar",suma); btCrear = new JButton("Crear",crear); btSalir = new JButton("Salir",salir); //Tipo de letra ArialBlack18 = new Font("Arial Black",Font.BOLD,18); //Color green = new Color(0,255,0); //Formato labelTitulo labelTitulo.setBounds(80,-60,200,150); labelTitulo.setFont(ArialBlack18); labelTitulo.setForeground(blue); labelTitulo.setVisible(true); //Formato de CrearMatriz btCrear.setBounds(80,50,130,30); btCrear.setToolTipText("Crea una matriz"); //Formato de Muliplica btMultiplica.setBounds(80,100,130,30); btMultiplica.setToolTipText("Mat[A] * Mat[B]"); //Formato de botonRestar btRestar.setBounds(80,150,130,30); btRestar.setToolTipText("Mat[A] - Mat[B]"); //Formato del botonSumar btSumar.setBounds(80,200,130,30); btSumar.setToolTipText("Mat[A] + Mat[B]"); //Formato de Transpuesta btTranspuesta.setBounds(80,250,130,30); btTranspuesta.setToolTipText("Mat[A]^-1"); //Formato del botonSalir btSalir.setBounds(80,300,130,30); //Agregando componentes al panel1 panel2.add(labelTitulo); panel2.add(btMultiplica); panel2.add(btCrear); panel2.add(btRestar); panel2.add(btSumar); panel2.add(btSalir); panel2.add(btTranspuesta); //Formato panel2 panel2.setBackground(green); panel2.setVisible(true); panel2.setBounds(0,0,300,380); //Argregamos componentes al panelPrincipal= panel.add(panel2); //BotonCrear btCrear.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) //throws IOException { if(ventanaAbierta==false) { ventanaAbierta=true; new CrearMatriz(); } else { JOptionPane.showMessageDialog(null,"Ya se crearon las Matrices"); } } }); m3 = new Matriz(ren2,col2); btSumar.addActionListener(new ActionListener() { Matriz m3;//(ren2,col2); public void actionPerformed(ActionEvent e) { m3 = new Matriz(ren2,col2); if(ventanaAbierta==true) { try { crearMat.SUMA(m1,m2); } catch(Exception nul) { System.out.println(nul); } } else { JOptionPane.showMessageDialog(null,"Ya se realizo la suma"); } } }); //BotonSalir btSalir.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { System.exit(0); } }); panel.setVisible(true); panel.setBounds(0,0,350,380); } class VentanaMatriz { private JFrame ventana; private JPanel panel; private JTextArea textArea1,textArea2; private JLabel mat1,mat2; private JTextField textField1; public VentanaMatriz() { panel = new JPanel(); panel.setLayout(null); ventana = new JFrame("Creacion de Matrices"); ventana.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { ventana.dispose(); } }); ventana.setContentPane(panel); ventana.setVisible(true); ventana.setResizable(false); ventana.setBounds(200,100,850,420); } public void inicializarComponentes() { //Colores black = new Color(0,0,0); white = new Color(255,255,255); blue = new Color(0,0,255); green = new Color(0,255,0); red = new Color(255,0,0); //Tipo de letra Verdana14 = new Font("Verdana",Font.BOLD,14); //Tipos de borde borderRed2 = BorderFactory.createLineBorder(red,2); borderBlue2 = BorderFactory.createLineBorder(blue,2); borderGreen2 = BorderFactory.createLineBorder(green,2); borderGreen4 = BorderFactory.createLineBorder(green,4); //Agregando componentes al panel1 panel.add(mat1); panel.add(textArea1); panel.add(mat2); panel.add(textArea2); //Formato panel2 panel.setBackground(blue); panel.setVisible(true); panel.setBounds(0,0,850,420); } } class CrearMatriz { public int col1,re1,ren2,col2; public Matriz m1,m2,m3; public CrearMatriz() { int col1,ren1,ren2,col2; ren2 = Integer.parseInt(JOptionPane.showInputDialog("Numero de Renglones Matriz A: ")); col2 = Integer.parseInt(JOptionPane.showInputDialog("Numero de Columnas Matriz A: ")); final Matriz m1= new Matriz(ren2,col2); ren2 = Integer.parseInt(JOptionPane.showInputDialog("Numero de Renglones Matriz B: ")); col2 = Integer.parseInt(JOptionPane.showInputDialog("Numero de Columnas Matriz B: ")); final Matriz m2= new Matriz(ren2,col2); m3 = new Matriz(ren2,col2); m1.llenarMatriz(); m2.llenarMatriz(); m1.printMat(); m2.printMat(); } public void SUMA(Matriz m1,Matriz m2) { Matriz m3; if(ventanaAbierta==false) { m3 = new Matriz(ren2,col2); if(valida.validaSumayResta(m1,m2)) { m3 = operacion.sumaMat(m1,m2); JOptionPane.showMessageDialog(null,"La suma es = "); m3.imprimeMatriz(); } else { JOptionPane.showMessageDialog(null,"No es posible hacer la suma"); } } } public void RESTA() { } //btSumar = new JButton("Sumar",suma); //BotonSumar //Mostrar matriz 1 y 2 // System.out.println("\n\n\nMatriz 1="); // m1.imprimeMatriz(); // System.out.println("\nMatriz 2="); //Poner en botones /* if(valida.validaSumayResta(m1,m2)) { m3 = operacion.sumaMat(m1,m2); JOptionPane.showMessageDialog(null,"La suma es = "); m3.imprimeMatriz(); } else { JOptionPane.showMessageDialog(null,"No es posible hacer la suma"); } if(valida.validaSumayResta(m1,m2)) { m3=operacion.restaMat(m1,m2); JOptionPane.showMessageDialog(null,"La resta es = "); m3.imprimeMatriz(); } else { JOptionPane.showMessageDialog(null,"No es posible hacer la resta"); } if(valida.validaMultiplicacion(m1,m2)){ m3=operacion.multiplicaMat(m1,m2); JOptionPane.showMessageDialog(null,"La multiplicacion es = "); m3.imprimeMatriz(); } else { JOptionPane.showMessageDialog(null,"No es posible hacer la multiplicacion"); } JOptionPane.showMessageDialog(null,"La multiplicacion es = "); m1=operacion.transpuesta(m1); m2=operacion.transpuesta(m2); */ } class Matriz { public JTextField matriz; //public JTextArea texto; private JFrame ventanaPrintMatriz; private JPanel panel2; int ren; int col; int pos[][]; public Matriz(int ren1, int col1) { ren = ren1; col = col1; pos = new int [ren][col];/*una matriz de enteros de renglon por columan*/ } public void llenarMatriz() { for(int i=0;i<ren;i++) for(int j=0;j<col;j++) pos[i][j]=(int) (Math.random()*10);/*la posicion i y j crea un entero random*/ } /*vuelve a recorrer los espacio de i y j*/ } //Esta clase era un metodo de CrearMatriz class ImprimirMatriz { public void ImprimirMatriz() { panel2 = new JPanel(); panel2.setLayout(null); ventanaPrintMatriz = new JFrame("Matriz"); ventana.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { //Practica2.ventanaAbierta=false; ventana.dispose(); } }); int i,j; int x=0,y=0; borderRed2 = BorderFactory.createLineBorder(red,2); white = new Color(255,255,255); red = new Color(255,0,0); black = new Color(0,0,0); blue = new Color(0,0,255); for(i=0;i<ren;i++) { for(j=0;j<col;j++) { matriz = new JTextField(" "+pos[i][j]); matriz.setBorder(borderRed2); matriz.setForeground(white); matriz.setBounds(x+25,y+25,25,25); matriz.setBackground(black); matriz.setEditable(false); matriz.setVisible(true); //Se incrementa la coordenada en X //para el siguiente Textfield no se encime x=x+35; //Agregamos el textField al panel panel2.add(matriz); } //Regreso las cordenadas de X a 0 para que el //siguiente renglon empieze en donde mismo x=0; //Incremento las coordenada Y para que se brinque //de linea y=y+35; } //Formato panel2 panel2.setBounds(150,150,350,380); panel2.setBackground(blue); //panel2.setEditable(false); panel2.setVisible(true); //Formato de Ventana ventanaPrintMatriz.setContentPane(panel2); ventanaPrintMatriz.setBounds(150,150,350,380); ventanaPrintMatriz.setResizable(false); ventanaPrintMatriz.setVisible(true); } } class Operaciones { public Matriz sumaMat(Matriz m1, Matriz m2) { Matriz m3; m3 = new Matriz(m1.ren, m1.col); for(int i=0;i<m1.col;i++) for(int j=0;j<m1.ren;j++) m3.pos[i][j]=m1.pos[i][j]+m2.pos[i][j]; return m3; } public Matriz restaMat(Matriz m1, Matriz m2) { Matriz m3; m3 = new Matriz(m1.ren, m1.col); for(int i=0;i<m1.col;i++) for(int j=0;j<m1.ren;j++) m3.pos[i][j]=m1.pos[i][j]-m2.pos[i][j]; return m3; } public Matriz multiplicaMat(Matriz m1, Matriz m2) { Matriz m3; m3 = new Matriz(m1.ren, m2.col); for(int i=0;i<m1.ren;i++) for(int j=0;j<m2.col;j++) { m3.pos[i][j]=0; for(int k=0;k<m1.col;k++) m3.pos[i][j]+=(m1.pos[i][k]*m2.pos[k][j]); } return m3; } public Matriz transpuesta(Matriz m1) { Matriz m3=new Matriz(m1.col,m1.ren); for(int i=0;i<m1.col;i++) for(int j=0;j<m1.ren;j++) m3.pos[i][j]=m1.pos[j][i]; return m3; } } class ValidacionesMatrices { public boolean validaSumayResta(Matriz m1, Matriz m2) { if((m1.ren==m2.ren) && (m1.col==m2.col)) return true; else return false; } public boolean validaMultiplicacion(Matriz m1, Matriz m2) { if(((m1.ren==m2.ren) && (m1.col==m2.col)) || (m1.col==m2.ren)) return true; else return false; } } public static void main(String[] args) { Practica2 practica2 = new Practica2(); practica2.inicializarComponentes(); } } Exc

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