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  • How can I save a directory tree to an array in PHP?

    - by Greg
    I'm trying to take a directory with the structure: top folder1 file1 folder2 file1 file2 And save it into an array like: array ( 'folder1' => array('file1'), 'folder2' => array('file1', 'file2') ) This way, I can easily resuse the tree throughout my site. I've been playing around with this code but it's still not doing what I want: private function get_tree() { $uploads = __RELPATH__ . DS . 'public' . DS . 'uploads'; $iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($uploads), RecursiveIteratorIterator::SELF_FIRST); $output = array(); foreach($iterator as $file) { $relativePath = str_replace($uploads . DS, '', $file); if ($file->isDir()) { if (!in_array($relativePath, $output)) $output[$relativePath] = array(); } } return $output; }

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  • Designing a peer to peer network

    - by Varun
    I am designing a simple peer to peer network. The basic architecture will be as follows: A central server- that keeps track of all the peers. The job of this server is to keep track of all the peers that join the network. Every peer could do things: a. Download a file from it's peer b. Push a file (send a file) to it's peer. Could anybody please tell me what would be the best design for such a system? What would be the problems that i might run into and so on. I am planning to use Java as the programming language to implement. Would it be a good choice? Also, is it necessary that i would need a Linux box to develop the system? or is it fine if i use a Windows machine? Your help will be much appreciated! Thanks!

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  • Console-App to get all open files for processes

    - by t.kehl
    Hi I am searching for a console-app (where I can pipe the output to a txt-file) which gives me a list of all current processes and the files which each process has open. The tool should also work when the user doesn't has administrativ-privilegues and it should also give file-path which are located on the network (UNC and absolute/mappings). Is there something like this which I can call from another tool and get the information? I am on a windows system. I have a open filename and need now to get the whole path for the file

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  • How to programmatically set the text of a cell of database in VB.Net?

    - by manuel
    I have a Microsoft Access database file connected to VB.NET. In the database table, I have a 'No.' and a 'Status' column. Then I have a textbox where I can input an integer. I also have a button, which will change the data cell in 'Status' where 'No.' = txtTitleNo.Text(), when I click it. Let's say I want the 'Status' cell to be changed to "Reserved". What codes should I put in the BtnReserve_Click? Here is the code: Public Class theForm Dim con As New OleDb.OleDbConnection Dim ds As New DataSet Dim daTitles As OleDb.OleDbDataAdapter Private Sub theForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load con.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=|DataDirectory|\db1.mdb" con.Open() daTitles = New OleDb.OleDbDataAdapter("SELECT * FROM Titles", con) daTitles.Fill(ds, "Titles") DataGridView1.DataSource = ds.Tables("Titles") DataGridView1.AutoResizeColumns() End Sub Private Sub BtnReserve_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnReserve.Click Dim daReserve As OleDb.OleDbCommand For i As Integer = 1 TReservedo DataGridView1.RowCount() If i = Val(txtTitleNo.Text()) Then daReserve = New OleDb.OleDbCommand("UPDATE Titles SET Status = 'Reserved' WHERE No = '" & i & "'", con) daReserve.ExecuteNonQuery() End If Next Dim cb As New OleDb.OleDbCommandBuilder(daTitles) daTitles.Update(ds, "Titles") End Sub This code still does not change the 'Status'. What should I do?

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  • ExecuteNonQuery: Connection property has not been initialized

    - by 20151012
    I get an error in my code: The error point at dbcom.ExecuteNonQuery();. Code(connection) public admin_addemp() { InitializeComponent(); con = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\EMPS.accdb;Persist Security Info=True"); con.Open(); ds.Tables.Add(dt); ds.Tables.Add(dt2); } Code (Save button) private void save_btn_Click(object sender, EventArgs e) { OleDbCommand check = new OleDbCommand(); check.Connection = con; check.CommandText = "SELECT COUNT(*) FROM employeeDB WHERE ([EmployeeName]=?)"; check.Parameters.AddWithValue("@EmployeeName", tb_name.Text); if (Convert.ToInt32(check.ExecuteScalar()) == 0) { dbcom2 = new OleDbCommand("SELECT EmployeeID FROM employeeDB WHERE EmployeeID='" + tb_id.Text + "'", con); OleDbParameter param = new OleDbParameter(); param.ParameterName = tb_id.Text; dbcom.Parameters.Add(param); OleDbDataReader read = dbcom2.ExecuteReader(); if (read.HasRows) { MessageBox.Show("The Employee ID '" + tb_id.Text + "' already exist. Please choose another Employee ID."); read.Dispose(); read.Close(); } else { string q = "INSERT INTO employeeDB (EmployeeID, EmployeeName, IC, Address, State, " + " Postcode, DateHired, Phone, ManagerName) VALUES ('" + tb_id.Text + "', " + " '" + tb_name.Text + "', '" + tb_ic.Text + "', '" + tb_add1.Text + "', '" + cb_state.Text + "', " + " '" + tb_postcode.Text + "', '" + dateTimePicker1.Value + "', '" + tb_hp.Text + "', '" + cb_manager.Text + "')"; dbcom = new OleDbCommand(q, con); dbcom.ExecuteNonQuery(); MessageBox.Show("New Employee '" + tb_name.Text + "'- Successfuly Added."); } } else { MessageBox.Show("Employee name '" + tb_name.Text + "' already added into the database"); } ds.Dispose(); } I'm using Microsoft Access 2010 as my database and this is stand alone system. Please help me.

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  • How to grab the lines AFTER a matched line in python

    - by toofly
    Hi All, I am an amateur using Python on and off for some time now. Sorry if this is a silly question, but I was wondering if anyone knew an easy way to grab a bunch of lines if the format in the input file is like this: " Heading 1 Line 1 Line 2 Line 3 Heading 2 Line 1 Line 2 Line 3 " I won't know how many lines are after each heading, but I want to grab them all. All I know is the name, or a regular expression pattern for the heading. The only way I know to read a file is the "for line in file:" way, but I don't know how to grab the lines AFTER the line I'm currently on. Hope this makes sense, and thanks for the help!

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  • Accessing and inheriting Windows Message for other Windows Message in Delphi

    - by HX_unbanned
    I am using WMSysCommand messages to modify Caption bar button ( Maximize / Minimize ) behaivor and recent update requiered to use WMNCHitTest, but I do not want to split these two related messages in multiplie procedures because of lengthy code. Can I access private declaration ( message ) from other message? And if I can - How to do it? procedure TForm1.WMNCHitTest(var Msg: TWMNCHitTest) ; begin SendMessage(Handle, HTCAPTION, WM_NCHitTest, 0); // or other wParam or lParam ???? end; procedure TForm1.WMSysCommand; begin if (Msg.CmdType = SC_MAXIMIZE or 61488) or (Msg.Result = htCaption or 2) then // if command is Maximize or reciever message of Caption Bar click begin if CheckWin32Version(6, 0) then Constraints.MaxHeight := 507 else Constraints.MaxHeight := 499; Constraints.MaxWidth := 0; end else if (Msg.CmdType = SC_MINIMIZE or 61472) or (Msg.Result = htCaption or 2) then // if command is Minimize begin if (EnsureRange(Width, 252, 510) >= (510 / 2)) then PreviewOpn.Caption := '<' else PreviewOpn.Caption := '>'; end; DefaultHandler(Msg); // reset Message handler to default ( Application ) end; Soo ... do I think correctly and sipmly do not know correct commands or I am thinking total bullsh*t? Regards. Thanks for any help...

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  • file_get_contents returns an empty string that is 354 bytes long.

    - by Kendall Crouch
    I'm trying to read the contents of a file and simply getting an empty string. The file exists on the server. I've tried some test with the following code and get the true to display: $filename = "includes/blah.php"; $filecontents = file_get_contents($filename, FILE_USE_INCLUDE_PATH); if ($filecontents === false) { echo(":FALSE:"); } else { echo(":TRUE:"); } var_dump($filecontents); The dump displays "string(354)" which is the correct size of the file. What am I doing wrong?

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  • Selecting More Than 1 Table in A Single Query

    - by Kamran
    I have 5 Tables in MS Access as Logs [Title, ID, Date, Author] Tape [Title, ID, Date, Author] Maps [Title, ID, Date, Author] VCDs [Title, ID, Date, Author] Book [Title, ID, Date, Author] I tried my level best through this code SELECT Logs.[Author], Tape.[Author], Maps.[Author], VCDs.[Author], Book.[Author] FROM Logs , Tape , Maps , VCDs, Book WHERE ((([Author] & " " & [Author] & " " & [Author] & " " & [Author]& " " & [Author]) Like "*" & [Type the Title or Any Part of the Title and Press Ok] & "*")); I want to select all of these fields in a single query. Suppose there is Adam as author of works in all tables. So when i put Adam in search box it should result from all tables. I know this can be done by having single table or renaming fields names but that's not required. Please help.

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  • Powershell - remote folder availability while counting files

    - by ziklop
    I´m trying to make a Powershell script that reports if there´s a file older than x minutes on remote folder. I make this: $strfolder = 'folder1 ..................' $pocet = (Get-ChildItem \\server1\edi1\folder1\*.* ) | where-object {($_.LastWriteTime -lt (Get-Date).AddDays(-0).AddHours(-0).AddMinutes(-20))} | Measure-Object if($pocet.count -eq 0){Write-Host $strfolder "OK" -foreground Green} else {Write-Host $strfolder "ERROR" -foreground Red} But there´s one huge problem. The folder is often unavailable for me bacause of the high load and I found out when there is no connection it doesn´t report an error but continues with zero in $pocet.count. It means it reports everything is ok when the folder is unavailable. I was thinking about using if(Test-Path..) but what about it became unavailable just after passing Test-Path? Does anyone has a solution please? Thank you in advance

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  • NSMutableArray accessing issue.

    - by Danegraphics
    I've searched and have no answer. I've created an NSMutableArray and am getting an EXC_BAD_ACCESS error in one place of access. Here. This is declaring in the .h file: NSMutableArray *buttons; ... @property (nonatomic, retain)NSMutableArray *buttons; And this is the synthesizing and implimenting: @synthesize buttons; ... - (id)init { self = [super init]; if(self != nil) { buttons = [[NSMutableArray alloc] init]; } return self; } ... -(void)addButtonWithImage:(Image*)image { Image *button = image; [buttons addObject:button]; [button release]; } ... -(void)replaceButtonAt:(int)num with:(Image*)image { Image *button = image; [buttons replaceObjectAtIndex:num withObject:button]; <<===EXC_BAD_ACCESS [button release]; } But when I use this: -(void)renderButton:(int)num atPoint:(CGPoint)point center:(BOOL)center{ Image *button = [buttons objectAtIndex:num]; [button renderAtPoint:point centerOfImage:center]; } It works

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  • Convert VBA to VBS

    - by dnLL
    I have a little VBA script with some functions that I would like to convert to a single VBS file. Here is an example of what I got: Private Declare Function GetPrivateProfileString Lib "kernel32" Alias "GetPrivateProfileStringA" (ByVal lpApplicationName As String, ByVal lpKeyName As Any, ByVal lpDefault As String, ByVal lpReturnedString As String, ByVal nSize As Long, ByVal lpFileName As String) As Long Private Function ReadIniFileString(ByVal Sect As String, ByVal Keyname As String) As String Dim Worked As Long Dim RetStr As String * 128 Dim StrSize As Long Dim iNoOfCharInIni As Integer Dim sIniString, sProfileString As String iNoOfCharInIni = 0 sIniString = "" If Sect = "" Or Keyname = "" Then MsgBox "Erreur lors de la lecture des paramètres dans " & IniFileName, vbExclamation, "INI" Access.Application.Quit Else sProfileString = "" RetStr = Space(128) StrSize = Len(RetStr) Worked = GetPrivateProfileString(Sect, Keyname, "", RetStr, StrSize, IniFileName) If Worked Then iNoOfCharInIni = Worked sIniString = Left$(RetStr, Worked) End If End If ReadIniFileString = sIniString End Function And then, I need to use this function to put some values in strings. VBS doesn't seem to like any of my var declaration ((Dim) MyVar As MyType). If I'm able to adapt that code to VBS, I should be able to do the rest of my functions too. How can I adapt/convert this to VBS? Thank you.

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  • Why can a public class not inherit from a less visible one?

    - by Dan Tao
    I apologize if this question has been asked before. I've searched SO somewhat and wasn't able to find it. I'm just curious what the rationale behind this design was/is. Obviously I understand that private/internal members of a base type cannot, nor should they, be exposed through a derived public type. But it seems to my naive thinking that the "hidden" parts could easily remain hidden while some base functionality is still shared and a new interface is exposed publicly. I'm thinking of something along these lines: Assembly X internal class InternalClass { protected virtual void DoSomethingProtected() { // Let's say this method provides some useful functionality. // Its visibility is quite limited (only to derived types in // the same assembly), but at least it's there. } } public class PublicClass : InternalClass { public void DoSomethingPublic() { // Now let's say this method is useful enough that this type // should be public. What's keeping us from leveraging the // base functionality laid out in InternalClass's implementation, // without exposing anything that shouldn't be exposed? } } Assembly Y public class OtherPublicClass : PublicClass { // It seems (again, to my naive mind) that this could work. This class // simply wouldn't be able to "see" any of the methods of InternalClass // from AssemblyX directly. But it could still access the public and // protected members of PublicClass that weren't inherited from // InternalClass. Does this make sense? What am I missing? }

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  • R.java doesn't exist...but it does! Problem started after installing ADT 10.0.0

    - by TenFour04
    I get this error when I try to clean a project: ERROR: Unable to open class file ....R.java: No such file or directory So I can't build my projects any more. But R.java is there in the gen folder and looks fine when I open it. This happens to every one of my projects. I tried completely deleting the Eclipse folder and reinstalling it (Helios on Windows) and Android ADT. No luck. I have also tried moving my workspace to a different drive. No luck. I made sure all folders in my workspace are not read only. This worked the first time, but immediately the error came back when I cleaned my project. This all started right after installing ADT 10.0. I am wondering if it somehow is building R.java as a read-only file. EDIT: Is deleting the eclipse directory sufficient to reset all of its configuration?

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  • Deploy PHP website to client server without showing PHP files

    - by ColmF
    I asked a recent question regarding the use of readfile() for remotely executing PHP, but maybe I'd be better off setting out the problem to see if I'm thinking the wrong way about things, so here goes: I have a PHP website that requires users to login, includes lots of forms, database connections and makes use of $_SESSION variables to keep track of various things I have a potential client who would like to use the functionality of my website, but on their own server, controlled by them. They would probably want to restyle the website using content and CSS files local to their server, but that's a problem for later I don't want to show them my PHP code, since that's the value of what I'd be providing. I had thought to do this with calls to include() from the client's server to mine, which at least keeps variable scope intact, but many sites (and the PHP docs) seem to recommend readfile(), file_get_contents() or similar. Ideally I'd like to have a simple wrapper file on the client's server for each "real" one on my server. Any suggestions as to how I might accomplish what I need? Thanks, ColmF

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  • Get location from where the Java code is executed

    - by drasto
    I have a swing Java application that preserves a lot of data (you can think of a game and its saves for example). Those data are stored in files rather then in database. I would like to keep this files near installation files(.jar file) of my application.Some users(like me) are used to delete default application folder of OS when it comes to large and I don't want them to loose their data this way. Any ideas how to do this easily ? How do I get the folder of the .jar file from program that is executing form that .jar file? Or how do I output files directly into some package? How do I create packages(folders inside jar) dynamically ? Or is there a simple way to distribute Java application in other formats then .jar and then store generated data in installation (sub)folder ? Thanks for reading

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  • Strings, regexp and files

    - by A Moose
    <?php $iprange = array( "^12\.34\.", "^12\.35\.", ); foreach($iprange as $var) { if (preg_match($var, $_SERVER['REMOTE_ADDR'])) { I'm looking to have a list that will constitute each of the values inside the array. Let's call it iprange.txt, from which I would extract the variable $iprange. I would also be updating the file with new ranges, but I also want to convert those strings to regexp if that's something that's needed in php, as it is in the above example. If you could help me with the two following issues: I understand that somehow I would be using an array include, but I'm not sure how to implement it. I would like to run a cron that would update the text file and turn it into a regexp acceptable for use in the above example, if you think regexp is a good idea and there isn't another option. I know how to apply a cron in a directadmin gui, but I don't know what the cronned file would look like.

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  • Dimensions of a collection, and how to traverse it in an efficient, elegant manner

    - by Bruce Ferguson
    I'm trying to find an elegant way to deal with multi-dimensional collections in Scala. My understanding is that I can have up to a 5 dimensional collection using tabulate, such as in the case of the following 2-Dimensional array: val test = Array.tabulate[Double](row,col)(_+_) and that I can access the elements of the array using for(i<-0 until row) { for(j<-0 until col) { test(i)(j) = 0.0 } } If I don't know a priori what I'm going to be handling, what might be a succinct way of determining the structure of the collection, and spanning it, without doing something like: case(Array(x)) => for(i<-1 until dim1) { test(i) = 0.0 } case(Array(x,y)) => for(i<-1 until dim1) { for(j<-1 until dim2) { test(i)(j) = 0.0 } } case(Array(x,y,z)) => ... The dimensional values n1, n2, n3, etc... are private, right? Also, would one use the same trick of unwrapping a 2-D array into a 1-D vector when dealing with n-Dimensional objects if I want a single case to handle the traversal? Thanks in advance Bruce

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  • Opening a file with a variable as name & checking for undefined values

    - by Harm De Weirdt
    Hello everyone. I'm having some problems writing data into a file using perl. sub startNewOrder{ my $name = makeUniqueFileName(); open (ORDER, ">$name.txt") or die "can't open file: $!\n"; format ORDER_TOP = PRODUCT<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<CODE<<<<<<<<AANTAL<<<<EENHEIDSPRIJS<<<<<<TOTAAL<<<<<<< . format ORDER = @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< @<<<<<<<< @<<<< @<<<<<< @<<<<< $title, $code, $amount, $price, $total . close (ORDER); } This is the sub I use to make the file. (I translated most of it) The makeUniqueFileName method makes a fileName based upon current time("minuteshoursdayOrder"). The problem now is that I have to write in this file in another sub. sub addToOrder{ print "give productcode:"; $code = <STDIN>; chop $code; print "Give amount:"; $amount = <STDIN>; chop $amount; if($inventory{$code} eq undef){ #Does the product exist? print "This product does not exist"; }elsif($inventory{$code}[2] < $amount && !defined($inventaris{$code}[2]) ){ #Is there enough in the inventory? print "There is not enough in stock" }else{ $inventory{$code}[2] -= $amount; #write in order file open (ORDER ">>$naam.txt") or die "can't open file: $!\n"; $title = $inventory{$code}[0]; $code = $code; $amount = $inventory{$code}[2]; $price = $inventory{$code}[1]; $total = $inventory{$code}[1]; write; close(ORDER); } %inventory is a hashtable that has the productcode as key and an array with the title, price and amount as value. There are two problems here: when I enter an invalid product number, I still have to enter an amount even while my code says it should print the error directly after checking if there is a product with the given code. The second problem is that the writing doesn't seem to work. It always give's a "No such file or directory" error. Is there a way to open the ORDER file i made in the first sub without having to make $name not local? Or just a way to write in this file? I really don't know how to start here. I can't really find much info on writing a file that has been closed before, and in a different sub.. Any help is appreciated, Harm

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  • Opening a file with a variable as name and checking for undefined values

    - by Harm De Weirdt
    I'm having some problems writing data into a file using Perl. sub startNewOrder{ my $name = makeUniqueFileName(); open (ORDER, ">$name.txt") or die "can't open file: $!\n"; format ORDER_TOP = PRODUCT<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<CODE<<<<<<<<AANTAL<<<<EENHEIDSPRIJS<<<<<<TOTAAL<<<<<<< . format ORDER = @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< @<<<<<<<< @<<<< @<<<<<< @<<<<< $title, $code, $amount, $price, $total . close (ORDER); } This is the sub I use to make the file. (I translated most of it.) The makeUniqueFileName method makes a fileName based upon current time("minuteshoursdayOrder"). The problem now is that I have to write to this file in another sub. sub addToOrder{ print "give productcode:"; $code = <STDIN>; chop $code; print "Give amount:"; $amount = <STDIN>; chop $amount; if($inventory{$code} eq undef){ #Does the product exist? print "This product does not exist"; }elsif($inventory{$code}[2] < $amount && !defined($inventaris{$code}[2]) ){ #Is there enough in the inventory? print "There is not enough in stock" }else{ $inventory{$code}[2] -= $amount; #write in order file open (ORDER ">>$naam.txt") or die "can't open file: $!\n"; $title = $inventory{$code}[0]; $code = $code; $amount = $inventory{$code}[2]; $price = $inventory{$code}[1]; $total = $inventory{$code}[1]; write; close(ORDER); } %inventory is a hashtable that has the productcode as key and an array with the title, price and amount as value. There are two problems here: when I enter an invalid product number, I still have to enter an amount even while my code says it should print the error directly after checking if there is a product with the given code. The second problem is that the writing doesn't seem to work. It always give's a "No such file or directory" error. Is there a way to open the ORDER file I made in the first sub without having to make $name not local? Or just a way to write in this file? I really don't know how to start here. I can't really find much info on writing a file that has been closed before, and in a different sub. Any help is appreciated, Harm

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  • deleting unaccessed files using python

    - by damon
    My django app parses some files uploaded by the user.It is possible that the file uploaded by the user may remain in the server for a long time ,without it being parsed by the app.This can increase in size if a lot of users upload a lot of files. I need to delete those files not recently parsed by the app -say not accessed for last 24 hours.I tried like this import os import time dirname = MEDIA_ROOT+my_folder filenames = os.listdir(dirname) filenames = [os.path.join(dirname,filename) for filename in filenames] for filename in filenames: last_access = os.stat(filename).st_atime #secs since epoch rtime = time.asctime(time.localtime(last_access)) print filename+'----'+rtime This shows the last accessed times for each file..But I am not sure how I can test if the file access time was within the last 24 hours..Can somebody help me out?

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  • Select Query Joined on Two Fields?

    - by btollett
    I've got a few tables in an access database: ID | LocationName 1 | Location1 2 | Location2 ID | LocationID | Date | NumProductsDelivered 1 | 1 | 12/10 | 3 2 | 1 | 01/11 | 2 3 | 1 | 02/11 | 2 4 | 2 | 11/10 | 1 5 | 2 | 12/10 | 1 ID | LocationID | Date | NumEmployees | EmployeeType 1 | 1 | 12/10 | 10 | 1 (=Permanent) 2 | 1 | 12/10 | 3 | 2 (=Temporary) 3 | 1 | 12/10 | 1 | 3 (=Support) 4 | 2 | 10/10 | 1 | 1 5 | 2 | 11/10 | 2 | 1 6 | 2 | 11/10 | 1 | 2 7 | 2 | 11/10 | 1 | 3 8 | 2 | 12/10 | 2 | 1 9 | 2 | 12/10 | 1 | 3 What I want to do is pass in the LocationID as a parameter and get back something like the following table. So, if I pass in 2 as my LocationID, I should get: Date | NumProductsDelivered | NumPermanentEmployees | NumSupportEmployees 10/10 | | 1 | 11/10 | 1 | 2 | 1 12/10 | 1 | 2 | 1 It seems like this should be a pretty simple query. I really don't even need the first table except as a way to fill in the combo box on the form from which the user chooses which location they want a report for. Unfortunately, everything I've done has resulted in me getting a lot more data than I should be getting. My confusion is in how to set up the join (presumably that's what I'm looking for here) given that I want both the date and locationID to be the same for each row in the result set. Any help would be much appreciated. Thanks.

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  • error: 'void Base::output()' is protected within this context

    - by Bill
    I'm confused about the errors generated by the following code. In Derived::doStuff, I can access Base::output directly by calling it. Why can't I create a pointer to output() in the same context that I can call output()? (I thought protected / private governed whether you could use a name in a specific context, but apparently that is incomplete?) Is my fix of writing callback(this, &Derived::output); instead of callback(this, Base::output) the correct solution? #include <iostream> using std::cout; using std::endl; template <typename T, typename U> void callback(T obj, U func) { ((obj)->*(func))(); } class Base { protected: void output() { cout << "Base::output" << endl; } }; class Derived : public Base { public: void doStuff() { // call it directly: output(); Base::output(); // create a pointer to it: // void (Base::*basePointer)() = &Base::output; // error: 'void Base::output()' is protected within this context void (Derived::*derivedPointer)() = &Derived::output; // call a function passing the pointer: // callback(this, &Base::output); // error: 'void Base::output()' is protected within this context callback(this, &Derived::output); } }; int main() { Derived d; d.doStuff(); }

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  • Nullable values in C++

    - by DanDan
    I'm creating a database access layer in native C++, and I'm looking at ways to support NULL values. Here is what I have so far: class CNullValue { public: static CNullValue Null() { static CNullValue nv; return nv; } }; template<class T> class CNullableT { public: CNullableT(CNullValue &v) : m_Value(T()), m_IsNull(true) { } CNullableT(T value) : m_Value(value), m_IsNull(false) { } bool IsNull() { return m_IsNull; } T GetValue() { return m_Value; } private: T m_Value; bool m_IsNull; }; This is how I'll have to define functions: void StoredProc(int i, CNullableT<int> j) { ...connect to database ...if j.IsNull pass null to database etc } And I call it like this: sp.StoredProc(1, 2); or sp.StoredProc(3, CNullValue::Null()); I was just wondering if there was a better way than this. In particular I don't like the singleton-like object of CNullValue with the statics. I'd prefer to just do sp.StoredProc(3, CNullValue); or something similar. How do others solve this problem?

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  • problem using getline with a unicode file

    - by hamishmcn
    UPDATE: Thank you to @Potatoswatter and @Jonathan Leffler for comments - rather embarrassingly I was caught out by the debugger tool tip not showing the value of a wstring correctly - however it still isn't quite working for me and I have updated the question below: If I have a small multibyte file I want to read into a string I use the following trick - I use getline with a delimeter of '\0' e.g. std::string contents_utf8; std::ifstream inf1("utf8.txt"); getline(inf1, contents_utf8, '\0'); This reads in the entire file including newlines. However if I try to do the same thing with a wide character file it doesn't work - my wstring only reads to the the first line. std::wstring contents_wide; std::wifstream inf2(L"ucs2-be.txt"); getline( inf2, contents_wide, wchar_t(0) ); //doesn't work For example my if unicode file contains the chars A and B seperated by CRLF, the hex looks like this: FE FF 00 41 00 0D 00 0A 00 42 Based on the fact that with a multibyte file getline with '\0' reads the entire file I believed that getline( inf2, contents_wide, wchar_t(0) ) should read in the entire unicode file. However it doesn't - with the example above my wide string would contain the following two wchar_ts: FF FF (If I remove the wchar_t(0) it reads in the first line as expected (ie FE FF 00 41 00 0D 00) Why doesn't wchar_t(0) work as a delimiting wchar_t of "00 00"? Thank you

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