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  • EBCDIC to ASCII conversion. Out of bound error. In C#.

    - by mekrizzy
    I tried creating a EBCDIC to ASCII convector in C# using this general conversion order(given below). Basically the program converted from ASCII to the equivalent integer and from there into EDCDIC using the order below. Now when I try compiling this in C# and try giving a EBCDIC string(got this from another file from another computer) it is showing 'Out of Bound' exception for some of the EBCDIC character. Why is this like this?? Is it about formating?? or C# ?? or windows? Extra: I tried just printing out all the ASCII and EBCDIC characters using a loop from 0..255 numbers but still its not showing many of the EBCDIC characters. Am I missing any standards? int[] eb2as = new int[256]{ 0, 1, 2, 3,156, 9,134,127,151,141,142, 11, 12, 13, 14, 15, 16, 17, 18, 19,157,133, 8,135, 24, 25,146,143, 28, 29, 30, 31, 128,129,130,131,132, 10, 23, 27,136,137,138,139,140, 5, 6, 7, 144,145, 22,147,148,149,150, 4,152,153,154,155, 20, 21,158, 26, 32,160,161,162,163,164,165,166,167,168, 91, 46, 60, 40, 43, 33, 38,169,170,171,172,173,174,175,176,177, 93, 36, 42, 41, 59, 94, 45, 47,178,179,180,181,182,183,184,185,124, 44, 37, 95, 62, 63, 186,187,188,189,190,191,192,193,194, 96, 58, 35, 64, 39, 61, 34, 195, 97, 98, 99,100,101,102,103,104,105,196,197,198,199,200,201, 202,106,107,108,109,110,111,112,113,114,203,204,205,206,207,208, 209,126,115,116,117,118,119,120,121,122,210,211,212,213,214,215, 216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231, 123, 65, 66, 67, 68, 69, 70, 71, 72, 73,232,233,234,235,236,237, 125, 74, 75, 76, 77, 78, 79, 80, 81, 82,238,239,240,241,242,243, 92,159, 83, 84, 85, 86, 87, 88, 89, 90,244,245,246,247,248,249, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57,250,251,252,253,254,255 }; The whole code is as follows: public string convertFromEBCDICtoASCII(string inputEBCDICString, int initialPos, int endPos) { string inputSubString = inputEBCDICString.Substring(initialPos, endPos); int[] e2a = new int[256]{ 0, 1, 2, 3,156, 9,134,127,151,141,142, 11, 12, 13, 14, 15, 16, 17, 18, 19,157,133, 8,135, 24, 25,146,143, 28, 29, 30, 31, 128,129,130,131,132, 10, 23, 27,136,137,138,139,140, 5, 6, 7, 144,145, 22,147,148,149,150, 4,152,153,154,155, 20, 21,158, 26, 32,160,161,162,163,164,165,166,167,168, 91, 46, 60, 40, 43, 33, 38,169,170,171,172,173,174,175,176,177, 93, 36, 42, 41, 59, 94, 45, 47,178,179,180,181,182,183,184,185,124, 44, 37, 95, 62, 63, 186,187,188,189,190,191,192,193,194, 96, 58, 35, 64, 39, 61, 34, 195, 97, 98, 99,100,101,102,103,104,105,196,197,198,199,200,201, 202,106,107,108,109,110,111,112,113,114,203,204,205,206,207,208, 209,126,115,116,117,118,119,120,121,122,210,211,212,213,214,215, 216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231, 123, 65, 66, 67, 68, 69, 70, 71, 72, 73,232,233,234,235,236,237, 125, 74, 75, 76, 77, 78, 79, 80, 81, 82,238,239,240,241,242,243, 92,159, 83, 84, 85, 86, 87, 88, 89, 90,244,245,246,247,248,249, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57,250,251,252,253,254,255 }; char chrItem = Convert.ToChar("0"); StringBuilder sb = new StringBuilder(); for (int i = 0; i < inputSubString.Length; i++) { try { chrItem = Convert.ToChar(inputSubString.Substring(i, 1)); sb.Append(Convert.ToChar(e2a[(int)chrItem])); sb.Append((int)chrItem); sb.Append((int)00); } catch (Exception ex) { Console.WriteLine("//" + ex.Message); return string.Empty; } } string result = sb.ToString(); sb = null; return result; }

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  • Controlling the USB from Windows

    - by b-gen-jack-o-neill
    Hi, I know this probably is not the easiest thing to do, but I am trying to connect Microcontroller and PC using USB. I dont want to use internal USART of Microcontroller or USB to RS232 converted, its project indended to help me understand various principles. So, getting the communication done from the Microcontroller side is piece of cake - I mean, when I know he protocol, its relativelly easy to implement it on Micro, becouse I am in direct control of evrything, even precise timing. But this is not the case of PC. I am not very familiar with concept of Windows handling the devices connected. In one of my previous question I ask about how Windows works with devices thru drivers. I understood that for internal use of Windows, drivers must have some default set of functions available to OS. I mean, when OS wants to access HDD, it calls HDD driver (which is probably internal in OS), with specific "questions" so that means that HDD driver has to be written to cooperate with Windows, to have write function in the proper place to be called by the OS. Something similiar is for GPU, Even DirectX, I mean DirectX must call specific functions from drivers, so drivers must be written to work with DX. I know, many functions from WinAPI works on their own, but even "simple" window must be in the end written into framebuffer, using MMIO to adress specified by drivers. Am I right? So, I expected that Windows have internal functions, parts of WinAPI designed to work with certain comonly used things. To call manufacturer-designed drivers. But this seems to not be entirely true becouse Windows has no way to communicate thru Paralel port. I mean, there is no function in the WinAPI to work with serial port, but there are funcions to work with HDD,GPU and so. But now there comes the part I am getting very lost at. So, I think Windows must have some built-in functions to communicate thru USB, becouse for example it handles USB flash memory. So, is there any WinAPI function designed to let user to operate USB thru that function, or when I want to use USB myself, do I have to call desired USB-driver function myself? Becouse all you need to send to USB controller is device adress and the infromation right? I mean, I don´t have to write any new drivers, am I right? Just to call WinAPI function if there is such, or directly call original USB driver. Does any of this make some sense?

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  • Trouble editing Word document with PHP

    - by bhoomi-nature
    I want to open a word document and edit it I am opening the word document from the server and at that time it's opening with garbage values (perhaps it's not being properly converted to UTF-8). When I delete those garbage values and insert something from a textarea to that file it is going to insert and from then on it opens properly. I would like the document to open with the English words in the document instead of garbage value - it's only the first opening that's broken at present. <? $filename = 'test.doc'; if(isset($_REQUEST['Submit'])){ $somecontent = stripslashes($_POST['somecontent']); // Let's make sure the file exists and is writable first. if (is_writable($filename)) { // In our example we're opening $filename in append mode. // The file pointer is at the bottom of the file hence // that's where $somecontent will go when we fwrite() it. if (!$handle = fopen($filename, 'w')) { echo "Cannot open file ($filename)"; exit; } // Write $somecontent to our opened fi<form action="" method="get"></form>le. if (fwrite($handle, $somecontent) === FALSE) { echo "Cannot write to file ($filename)"; exit; } echo "Success, wrote ($somecontent) to file ($filename) <a href=".$_SERVER['PHP_SELF']."> - Continue - "; fclose($handle); } else { echo "The file $filename is not writable"; } } else { // get contents of a file into a string $handle = fopen($filename, 'r'); $somecontent = fread($handle, filesize($filename)); ?> <h1>Edit file <? echo $filename ;?></h1> <form name="form1" method="post" action=""> <p> <textarea name="somecontent" cols="80" rows="10"><? echo $somecontent ;?></textarea> </p> <p> <input type="submit" name="Submit" value="Submit"> </p> </form> <? fclose($handle); } ?>

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  • Converting text into numeric in xls using Java

    - by Work World
    When I create excel sheet through java ,the column which has number datatype in the oracle table, get converted to text format in excel.I want it to remain in the number format.Below is my code snippet for excel creation. FileWriter fw = new FileWriter(tempFile.getAbsoluteFile(),true); // BufferedWriter bw = new BufferedWriter(fw); HSSFWorkbook wb = new HSSFWorkbook(); HSSFSheet sheet = wb.createSheet("Excel Sheet"); //Column Size of excel for(int i=0;i<10;i++) { sheet.setColumnWidth((short) i, (short)8000); } String userSelectedValues=result; HSSFCellStyle style = wb.createCellStyle(); ///HSSFDataFormat df = wb.createDataFormat(); style.setFillForegroundColor(HSSFColor.GREY_25_PERCENT.index); style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND); //style.setDataFormat(df.getFormat("0")); HSSFFont font = wb.createFont(); font.setColor(HSSFColor.BLACK.index); font.setBoldweight((short) 700); style.setFont(font); int selecteditems=userSelectedValues.split(",").length; // HSSFRow rowhead = sheet.createRow((short)0); //System.out.println("**************selecteditems************" +selecteditems); for(int k=0; k<selecteditems;k++) { HSSFRow rowhead = sheet.createRow((short)k); if(userSelectedValues.contains("O_UID")) { HSSFCell cell0 = rowhead.createCell((short) k); cell0.setCellValue("O UID"); cell0.setCellStyle(style); k=k+1; } ///some columns here.. } int index=1; for (int i = 0; i<dataBeanList.size(); i++) { odb=(OppDataBean)dataBeanList.get(i); HSSFRow row = sheet.createRow((short)index); for(int j=0;j<selecteditems;j++) { if(userSelectedValues.contains("O_UID")) { row.createCell((short)j).setCellValue(odb.getUID()); j=j+1; } } index++; } FileOutputStream fileOut = null; try { fileOut = new FileOutputStream(path.toString()+"/temp.xls"); } catch (FileNotFoundException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } try { wb.write(fileOut); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { fileOut.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); }

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  • C# Read Byte [] to Image

    - by LucasGuitar
    I have an application which I'm adding pictures and these are automatically converted to binary and stored in a single file. how can I save several images, I keep in an XML file start and size of each set of refente to an image byte. But it has several images in bytes, whenever I try to select a different set of bytes just opening the same image. I would like your help to be able to fix this and open different images. Code //Add Image private void btAddImage_Click(object sender, RoutedEventArgs e) { OpenFileDialog op = new OpenFileDialog(); op.Title = "Selecione a Imagem"; op.Filter = "All supported graphics|*.jpg;*.jpeg;*.png|" + "JPEG (*.jpg;*.jpeg)|*.jpg;*.jpeg|" + "Portable Network Graphic (*.png)|*.png"; if (op.ShowDialog() == true) { imgPatch.Source = new BitmapImage(new Uri(op.FileName)); txtName.Focus(); } } //Convert Image private void btConvertImage_Click(object sender, RoutedEventArgs e) { if (String.IsNullOrEmpty(txtName.Text)) { txtName.Focus(); MessageBox.Show("Preencha o Nome", "Error"); } else { save(ConvertFileToByteArray(op.FileName), txtName.Text); } } //Image to Byte Array private static byte[] ConvertFileToByteArray(String FilePath) { return File.ReadAllBytes(FilePath); } //Save Binary File and XML File public void save(byte[] img, string nome) { FileStream f; long ini, fin = img.Length; if (!File.Exists("Escudos.bcf")) { f = new FileStream("Escudos.bcf", FileMode.Create); ini = 0; } else { f = new FileStream("Escudos.bcf", FileMode.Append); ini = f.Length + 1; bin = new TestBinarySegment(); } bin.LoadAddSave("Escudos.xml", "Brasileiro", nome, ini, fin); BinaryWriter b = new BinaryWriter(f); b.Write(img); b.Close(); f.Dispose(); } //Load Image from Byte private void btLoad_Click(object sender, RoutedEventArgs e) { getImageFromByte(); } //Byte to Image public void getImageFromByte(int start, int length) { using (FileStream fs = new FileStream("Escudos.bcf", FileMode.Open)) { byte[] iba = new byte[fs.Length+1]; fs.Read(iba, start, length); Image image = new Image(); image.Source = BitmapFrame.Create(fs, BitmapCreateOptions.None, BitmapCacheOption.OnLoad); imgPatch2.Source = image.Source; } }

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  • Adding the text area input to a list with jquery

    - by amylynn83
    I am making a shopping list app. When an item is added to the text input, it should be converted into a list item with a class of "tile" and added to the beginning of the list with a class of ".shopping_item_list". Here is my HTML: <section> <h1 class="outline">Shopping List Items</h1> <ul class="shopping_item_list"> <li class="tile">Flowers<span class="delete">Delete</span></li> </ul> </section> My jQuery: $("input[name='shopping_item']").change(function() { var item = $(this).val(); $("<li class='tile'>+ item +</li>").prependTo(".shopping_item_list"); $(".tile").removeClass("middle"); $(".shopping_item_list li:nth-child(3n+2)").addClass("middle"); }); This isn't working, and I can't figure out why. I'm new to jQuery. Also, I need to add the "delete" span to the list item and am not sure how. Thanks for any help you can offer! Edited to add: Thanks to the feedback here, I was able to make it work with: $("input[name='shopping_item']").change(function() { var item = $(this).val(); $("<li class='tile'>" + item + "<span class='delete'>Delete</span>" + " </li>").prependTo(".shopping_item_list"); $(".tile").removeClass("middle"); $(".shopping_item_list li:nth-child(3n+2)").addClass("middle"); }); However, in my jquery, I have functions for the classes "tile" and "delete" that are not working for newly added items. // hide delete button $(".delete").hide(); // delete square $(".tile").hover(function() { $(this).find(".delete").toggle(); }); $(".tile").on("click", ".delete", function() { $(this).closest("li.tile").remove(); $(".tile").removeClass("middle"); $(".shopping_item_list li:nth-child(3n+2)").addClass("middle"); }); // cross off list $(".tile").click(function() { $(this).toggleClass("deleteAction"); }); The new items, which have these classes applied aren't using these functions at all. Do I need to add the functions below the add item? Does the order in which they appear in my js file matter? Do I need to add some kind of function?

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  • java.lang.NumberFormatException: unable to parse '' as integer one more time

    - by Quzziy
    I will take two numbers from user, but this number from EditText must be converted to int. I think it should be working, but I still have problem with compilation code in Android Studio. CatLog show error in line with: int wiek = Integer.parseInt(wiekEditText.getText().toString()); Below is my full Android code: public class MyActivity extends ActionBarActivity { int Wynik; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_my); int Tmax, RT; EditText wiekEditText = (EditText) findViewById(R.id.inWiek); EditText tspoczEditText = (EditText) findViewById(R.id.inTspocz); int wiek = Integer.parseInt(wiekEditText.getText().toString()); int tspocz = Integer.parseInt(tspoczEditText.getText().toString()); Tmax = 220 - wiek; RT = Tmax - tspocz; Wynik = 70*RT/100 + tspocz; final EditText tempWiekEdit = wiekEditText; TabHost tabHost = (TabHost) findViewById(R.id.tabHost); //Do TabHost'a z layoutu tabHost.setup(); TabHost.TabSpec tabSpec = tabHost.newTabSpec("Calc"); tabSpec.setContent(R.id.Calc); tabSpec.setIndicator("Calc"); tabHost.addTab(tabSpec); tabSpec = tabHost.newTabSpec("Hints"); tabSpec.setContent(R.id.Hints); tabSpec.setIndicator("Hints"); tabHost.addTab(tabSpec); final Button Btn = (Button) findViewById(R.id.Btn); Btn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Toast.makeText(getApplicationContext(),"blablabla"+ "Wynik",Toast.LENGTH_SHORT).show(); } }); wiekEditText.addTextChangedListener(new TextWatcher() { @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) { } @Override public void onTextChanged(CharSequence s, int start, int before, int count) { Btn.setEnabled(!(tempWiekEdit.getText().toString().trim().isEmpty())); } @Override public void afterTextChanged(Editable s) { } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.my, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } }

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  • php: parsing and converting array structure

    - by mwb
    I need to convert one array structure into another array structure. I hope someone will find it worthy their time to show how this could be done in a simple manner. It's a little above my array manipulation skills. The structure we start out with looks like this: $cssoptions = array( array( 'group' => 'Measurements' , 'selector' => '#content' , 'rule' => 'width' , 'value' => '200px' ) // end data set , array( 'group' => 'Measurements' , 'selector' => '#content' , 'rule' => 'margin-right' , 'value' => '20px' ) // end data set , array( 'group' => 'Colors' , 'selector' => '#content' , 'rule' => 'color' , 'value' => '#444' ) // end data set , array( 'group' => 'Measurements' , 'selector' => '.sidebar' , 'rule' => 'margin-top' , 'value' => '10px' ) // end data set ); // END $cssoptions It's a collection of discreet datasets, each consisting of an array that holds two key = value pairs describing a 'css-rule' and a 'css-rule-value'. Further, each dataset holds a key = value pair describing the 'css-selector-group' that the 'css-rule' should blong to, and a key = value pair describing a 'rule-group' that should be used for structuring the rendering of the final css into a neat css code block arranged by the kind of properties they describe (colors, measurement, typography etc..) Now, I need to parse that, and turn it into a new structure, where the: 'rule' => 'rule-name' , 'value' => 'value-string' for each dataset is converted into: 'rule-name' => 'value-string' ..and then placed into a new array structure where all 'rule-name' = 'value-string' pairs should be aggregated under the respective 'selector-values' Like this: '#content' => array( 'width' => '200px' , 'margin-right' => '20px' ) // end selecor block ..and finally all those blocks should be grouped under their respective 'style-groups', creating a final resulting array structure like this: $css => array( 'Measurements' => array( '#content' => array( 'width' => '200px' , 'margin-right' => '20px' ) // end selecor block , '.sidebar' => array( 'margin-top' => '10px' ) // end selector block ) // end rule group , 'Colors' => array( '#content' => array( 'color' => '#444' ) // end selector block ) // end rule group ); // end css

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  • Integrating HP Systems Insight Manager into an existing environment

    - by ewwhite
    I'm working with an environment that spans multiple data centers/sites and consists primarily of HP ProLiant servers (G5-G7) running Linux. The mix is 30% RHEL/CentOS, the rest are Gentoo :(. I also have a few dozen virtual machines running back-office and Windows servers on VMWare ESX hosts. I run OpenNMS to pull SNMP data from the various server nodes and networking devices. While OpenNMS works wonderfully for up/down, thresholds and notifications, it's native handling of traps is a little rough and the graphs are not particularly pretty. I use Orca/RRD graphs for performance trending and nice graphs. I'm tasked with inventorying the environment and wanted to come up with a clean way to organize server information. Since my environment is mostly HP, I've been playing with HP Systems Insight Manager as a way to extract server data and to deploy HP health/monitoring packages and firmware. The Gentoo systems eventually have to be converted to CentOS, so getting a quick assessment of what hardware is where would be great. Although I've read through a few hundred pages of HP manuals, I'm having a difficult time understanding how to get HP SIM to do what I want, though. My main problems are: I have about 40 subnets to deal with; 98% connected with private lines to facilities across the globe. I don't want to initiate an HP SIM discovery only to pull back every piece of intermediate networking hardware and equipment from all of the locations. I'd like this to focus on the servers. I have OpenNMS configured to accept traps. I don't want HP SIM to duplicate that effort. It seems like the built-in software deployment tool wants to overwrite the trapsink parameters for the systems it encounters during discovery. I have about 10 administrative username/password combinations in use across this infrastructure. Is there a more efficient way to get HP SIM to do the discovery or break discovery into manageable chunks? In terms of general workflow, do people typically install the HP Management Agents during the initial OS deployment (e.g. kickstart post script) or afterwards from HP SIM? Is HP SIM too thick/fat to be an inventory tool? I can't tell if it's meant to be used standalone or alongside other monitoring products. Since the majority of the systems I'm trying to track are those running Gentoo (in order to plan the move to CentOS), is there any way for HP SIM to extract system model information from them ( like dmidecode)? I have systems here where I may have an SSH key established, but not direct user or login access. Is there a way for me to import an SSH private/public key pair into HP SIM to reach out to the servers that can't accept standard credentials? There are a handful of sites where I have inconsistent access or have a double-NAT situation. I may be able to poke a server, but it may not be able to find its way back to the management system. Is there a workaround for this? The certificate configuration for HP SIM seems complicated. What is the preferred setup for trust between systems? I'd also appreciate any notes or recommendations to using this product. Or if there's a better way to do this, I'd like to know.

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  • How to recover data files from xampp-windows to xampp-linux after crash?

    - by David Buehler
    My Windows box died after I developed a database in xampp on it; fortunately I have a backup of the entire F:/TestWeb/Xampp partition. Unfortunately, I did not do an Export (nor dump) of the "Lws2" database before the crash. I have replaced the defunct machine with one running Mint7 (based on Ubuntu 9.04 "Jaunty Jackalope") and installed xampp-linux into the /opt partition, so the new xampp now runs fine in /opt/lampp, and says all the elements are secured by passwords (which I just assigned during this installation.) I assumed that Xamp-Windows installed in November would migrate easily to xampp-linux installed iin February -- a bad assumption. It apparently would have been simple if I had known enough to do an Export or a Dump before the crash, but.... The backup was done to a Network Attached Storage drive, which is formatted as "vfat" so the backup does not carry with it any valid ownership permissions from MySql on NTFS. I now see from my backup that the old data resided in \TestWeb\Xampp\Mysql\Data\Lws2\ and consists of 7 ".frm" files which define my tables. The actual data -- I suppose a ".sql" file or files -- has disappeared, and I am resigning myself to two days of retyping it. But I do not wish to do the table layouts all over again. So I copied Data tree to /opt/lampp/Data -- PhpMyAdmin does not see it. So I copied Lws2 tree to /opt/lampp/Lws2 -- PhpMyAdmin does not see it. So I copied Data tree to /opt/lampp/var/mysql/Data -- PhpMyAdmin does not see it. So I copied Lws2 tree to /opt/lampp/var/mysql/Lws2 -- PhpMyAdmin does not see it. So I adjusted all the permissions to stop saying owner "nobody" to owner "root" and gave full permissions to all groups and to all others, with permissions percolating down, in all 4 trees. You guessed it -- PhpMyAdmin does not see any database named Lws2, only its 4 default ones. I double-checked the permissions and rebooted Linux and repeated the tests. At some point in that process I did see PhpMyAdmin showing "lws2(7)" but when I clicked on it I saw a "no table found" message. I have not been able to recreate that experience. Apparently there are some setup files for MySql and for PhpMyAdmin which need to be set up by running a wizard or two or by editing the files directly. I grepped the TestWeb tree and found an old "ldir = "C:TestWeb\Xampp\MySql\" and a "DataDir = C:TestWeb\Xampp\MySql\" in a .php file and in a .bat file, but I cannot find the corresponding config file names on the /opt partition/ -- so it looks as if these wizards have not been run to create them. What config files files does Linux use to setup MySql config files for PhpMyAdmin? What wizards do I need to run to point the MySql engine and the PhpMyAdmin at the folder /opt/lampp/data/ with its lws2 folder inside it? Or which files do I need to edit, with a sample of what it normally says under Linux? Incidentally, I remember I converted from MyISAM with its .MYD and .MYI files to InnoDB after entering only a small amount of the data -- and I do not know what file types to look for -- perhaps my data is still there but under another guise or in another place? Is it something as simple as linux needing to see "/data/" instead of /Data? I will check that out while waiting for a response. If anyone can point me to documentation that discusses this level of detail -- I will read it avidly! In any case, thanks for any clarification you can give on this thorny problem. wizdum

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  • synchronization of file locations between two machines

    - by intuited
    Although similar threads have been asked on this site and its siblings before, I've not managed to glean the answer to this persistent question. Any help is much appreciated. The situation: I've got two laptops; both contain a ton of music. Sometimes I move these music files to different locations, or change the metadata in them, or convert them to a different format. I might do any of these things on either machine. I rarely do all of them at once — ie it's unlikely that I'll convert a file's format and move it to a different location all in one go. I'd like to be able to synchronize these changes without having to sift through everything that was renamed or moved. I'm familiar with rsync but I find it inadequate, because although it can compute checksums, it doesn't have any way to store them. So if a file differs, it can't figure out which side it changed on. This also means that it can't attempt to match a missing file to a new one with the same checksum (ie a move) if the filesize and date are the same, it , so it takes an epoch to do a sync on a large repository. I would like to only check the checksum if the files even if you turn on checksumming, it still doesn't use it intelligently: ie it checksums files even if the sizes differ. IIRC. it's not able to use file metadata as a means of file comparison. this is sort of a wishlist item but it seems doable. I've also looked into rsnapshot, but its requirement to create a full backup is impractical in this situation. I don't need a backup, I just need a record of what file with each hash was where when. Unison seems like it might be able to do something vaguely along these lines, but I'm loathe to spend hours wading through its details only to discover that it's sadly lacking. Plus, it's fun asking questions on here. What I'd like is a tool that does something along these lines: keeps track of file checksums or of actual renames, possibly using inotify to greatly reduce resource consumption/latency stores a database containing this info, along with other pertinencies like the file format and metadata, the actual inode, the filename history, etc. uses this info to provide more-intelligent synchronization with a counterpart on the other side. So for example: if a file has been converted from flac to ogg, but kept the same base filename, or the same metadata, it should be able to send the new version over, and the other side should delete the original. Probably it should actually sequester it somewhere in case they or you screwed up, but that's a detail. And then when the transaction is done, the state is logged so that the next time the two interact they can work out their differences. Maybe all this metadata stuff is a fancy pipe dream. I would actually be pretty happy if there was something out there that could just use checksums in an intelligent way. This would be sort of like having the intelligence of something like git, minus the need to duplicate data in an index/backup/etc (and branching, and checkouts, and all the other great stuff that RCSs do. basically just fast forward commit pushes are all I want, with maybe the option to roll back.) So is there something out there that can do this? If not, can someone suggest a good way to start making it?

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  • Basics of Join Predicate Pushdown in Oracle

    - by Maria Colgan
    Happy New Year to all of our readers! We hope you all had a great holiday season. We start the new year by continuing our series on Optimizer transformations. This time it is the turn of Predicate Pushdown. I would like to thank Rafi Ahmed for the content of this blog.Normally, a view cannot be joined with an index-based nested loop (i.e., index access) join, since a view, in contrast with a base table, does not have an index defined on it. A view can only be joined with other tables using three methods: hash, nested loop, and sort-merge joins. Introduction The join predicate pushdown (JPPD) transformation allows a view to be joined with index-based nested-loop join method, which may provide a more optimal alternative. In the join predicate pushdown transformation, the view remains a separate query block, but it contains the join predicate, which is pushed down from its containing query block into the view. The view thus becomes correlated and must be evaluated for each row of the outer query block. These pushed-down join predicates, once inside the view, open up new index access paths on the base tables inside the view; this allows the view to be joined with index-based nested-loop join method, thereby enabling the optimizer to select an efficient execution plan. The join predicate pushdown transformation is not always optimal. The join predicate pushed-down view becomes correlated and it must be evaluated for each outer row; if there is a large number of outer rows, the cost of evaluating the view multiple times may make the nested-loop join suboptimal, and therefore joining the view with hash or sort-merge join method may be more efficient. The decision whether to push down join predicates into a view is determined by evaluating the costs of the outer query with and without the join predicate pushdown transformation under Oracle's cost-based query transformation framework. The join predicate pushdown transformation applies to both non-mergeable views and mergeable views and to pre-defined and inline views as well as to views generated internally by the optimizer during various transformations. The following shows the types of views on which join predicate pushdown is currently supported. UNION ALL/UNION view Outer-joined view Anti-joined view Semi-joined view DISTINCT view GROUP-BY view Examples Consider query A, which has an outer-joined view V. The view cannot be merged, as it contains two tables, and the join between these two tables must be performed before the join between the view and the outer table T4. A: SELECT T4.unique1, V.unique3 FROM T_4K T4,            (SELECT T10.unique3, T10.hundred, T10.ten             FROM T_5K T5, T_10K T10             WHERE T5.unique3 = T10.unique3) VWHERE T4.unique3 = V.hundred(+) AND       T4.ten = V.ten(+) AND       T4.thousand = 5; The following shows the non-default plan for query A generated by disabling join predicate pushdown. When query A undergoes join predicate pushdown, it yields query B. Note that query B is expressed in a non-standard SQL and shows an internal representation of the query. B: SELECT T4.unique1, V.unique3 FROM T_4K T4,           (SELECT T10.unique3, T10.hundred, T10.ten             FROM T_5K T5, T_10K T10             WHERE T5.unique3 = T10.unique3             AND T4.unique3 = V.hundred(+)             AND T4.ten = V.ten(+)) V WHERE T4.thousand = 5; The execution plan for query B is shown below. In the execution plan BX, note the keyword 'VIEW PUSHED PREDICATE' indicates that the view has undergone the join predicate pushdown transformation. The join predicates (shown here in red) have been moved into the view V; these join predicates open up index access paths thereby enabling index-based nested-loop join of the view. With join predicate pushdown, the cost of query A has come down from 62 to 32.  As mentioned earlier, the join predicate pushdown transformation is cost-based, and a join predicate pushed-down plan is selected only when it reduces the overall cost. Consider another example of a query C, which contains a view with the UNION ALL set operator.C: SELECT R.unique1, V.unique3 FROM T_5K R,            (SELECT T1.unique3, T2.unique1+T1.unique1             FROM T_5K T1, T_10K T2             WHERE T1.unique1 = T2.unique1             UNION ALL             SELECT T1.unique3, T2.unique2             FROM G_4K T1, T_10K T2             WHERE T1.unique1 = T2.unique1) V WHERE R.unique3 = V.unique3 and R.thousand < 1; The execution plan of query C is shown below. In the above, 'VIEW UNION ALL PUSHED PREDICATE' indicates that the UNION ALL view has undergone the join predicate pushdown transformation. As can be seen, here the join predicate has been replicated and pushed inside every branch of the UNION ALL view. The join predicates (shown here in red) open up index access paths thereby enabling index-based nested loop join of the view. Consider query D as an example of join predicate pushdown into a distinct view. We have the following cardinalities of the tables involved in query D: Sales (1,016,271), Customers (50,000), and Costs (787,766).  D: SELECT C.cust_last_name, C.cust_city FROM customers C,            (SELECT DISTINCT S.cust_id             FROM sales S, costs CT             WHERE S.prod_id = CT.prod_id and CT.unit_price > 70) V WHERE C.cust_state_province = 'CA' and C.cust_id = V.cust_id; The execution plan of query D is shown below. As shown in XD, when query D undergoes join predicate pushdown transformation, the expensive DISTINCT operator is removed and the join is converted into a semi-join; this is possible, since all the SELECT list items of the view participate in an equi-join with the outer tables. Under similar conditions, when a group-by view undergoes join predicate pushdown transformation, the expensive group-by operator can also be removed. With the join predicate pushdown transformation, the elapsed time of query D came down from 63 seconds to 5 seconds. Since distinct and group-by views are mergeable views, the cost-based transformation framework also compares the cost of merging the view with that of join predicate pushdown in selecting the most optimal execution plan. Summary We have tried to illustrate the basic ideas behind join predicate pushdown on different types of views by showing example queries that are quite simple. Oracle can handle far more complex queries and other types of views not shown here in the examples. Again many thanks to Rafi Ahmed for the content of this blog post.

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  • Parallelism in .NET – Part 6, Declarative Data Parallelism

    - by Reed
    When working with a problem that can be decomposed by data, we have a collection, and some operation being performed upon the collection.  I’ve demonstrated how this can be parallelized using the Task Parallel Library and imperative programming using imperative data parallelism via the Parallel class.  While this provides a huge step forward in terms of power and capabilities, in many cases, special care must still be given for relative common scenarios. C# 3.0 and Visual Basic 9.0 introduced a new, declarative programming model to .NET via the LINQ Project.  When working with collections, we can now write software that describes what we want to occur without having to explicitly state how the program should accomplish the task.  By taking advantage of LINQ, many operations become much shorter, more elegant, and easier to understand and maintain.  Version 4.0 of the .NET framework extends this concept into the parallel computation space by introducing Parallel LINQ. Before we delve into PLINQ, let’s begin with a short discussion of LINQ.  LINQ, the extensions to the .NET Framework which implement language integrated query, set, and transform operations, is implemented in many flavors.  For our purposes, we are interested in LINQ to Objects.  When dealing with parallelizing a routine, we typically are dealing with in-memory data storage.  More data-access oriented LINQ variants, such as LINQ to SQL and LINQ to Entities in the Entity Framework fall outside of our concern, since the parallelism there is the concern of the data base engine processing the query itself. LINQ (LINQ to Objects in particular) works by implementing a series of extension methods, most of which work on IEnumerable<T>.  The language enhancements use these extension methods to create a very concise, readable alternative to using traditional foreach statement.  For example, let’s revisit our minimum aggregation routine we wrote in Part 4: double min = double.MaxValue; foreach(var item in collection) { double value = item.PerformComputation(); min = System.Math.Min(min, value); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, we’re doing a very simple computation, but writing this in an imperative style.  This can be loosely translated to English as: Create a very large number, and save it in min Loop through each item in the collection. For every item: Perform some computation, and save the result If the computation is less than min, set min to the computation Although this is fairly easy to follow, it’s quite a few lines of code, and it requires us to read through the code, step by step, line by line, in order to understand the intention of the developer. We can rework this same statement, using LINQ: double min = collection.Min(item => item.PerformComputation()); Here, we’re after the same information.  However, this is written using a declarative programming style.  When we see this code, we’d naturally translate this to English as: Save the Min value of collection, determined via calling item.PerformComputation() That’s it – instead of multiple logical steps, we have one single, declarative request.  This makes the developer’s intentions very clear, and very easy to follow.  The system is free to implement this using whatever method required. Parallel LINQ (PLINQ) extends LINQ to Objects to support parallel operations.  This is a perfect fit in many cases when you have a problem that can be decomposed by data.  To show this, let’s again refer to our minimum aggregation routine from Part 4, but this time, let’s review our final, parallelized version: // Safe, and fast! double min = double.MaxValue; // Make a "lock" object object syncObject = new object(); Parallel.ForEach( collection, // First, we provide a local state initialization delegate. () => double.MaxValue, // Next, we supply the body, which takes the original item, loop state, // and local state, and returns a new local state (item, loopState, localState) => { double value = item.PerformComputation(); return System.Math.Min(localState, value); }, // Finally, we provide an Action<TLocal>, to "merge" results together localState => { // This requires locking, but it's only once per used thread lock(syncObj) min = System.Math.Min(min, localState); } ); Here, we’re doing the same computation as above, but fully parallelized.  Describing this in English becomes quite a feat: Create a very large number, and save it in min Create a temporary object we can use for locking Call Parallel.ForEach, specifying three delegates For the first delegate: Initialize a local variable to hold the local state to a very large number For the second delegate: For each item in the collection, perform some computation, save the result If the result is less than our local state, save the result in local state For the final delegate: Take a lock on our temporary object to protect our min variable Save the min of our min and local state variables Although this solves our problem, and does it in a very efficient way, we’ve created a set of code that is quite a bit more difficult to understand and maintain. PLINQ provides us with a very nice alternative.  In order to use PLINQ, we need to learn one new extension method that works on IEnumerable<T> – ParallelEnumerable.AsParallel(). That’s all we need to learn in order to use PLINQ: one single method.  We can write our minimum aggregation in PLINQ very simply: double min = collection.AsParallel().Min(item => item.PerformComputation()); By simply adding “.AsParallel()” to our LINQ to Objects query, we converted this to using PLINQ and running this computation in parallel!  This can be loosely translated into English easily, as well: Process the collection in parallel Get the Minimum value, determined by calling PerformComputation on each item Here, our intention is very clear and easy to understand.  We just want to perform the same operation we did in serial, but run it “as parallel”.  PLINQ completely extends LINQ to Objects: the entire functionality of LINQ to Objects is available.  By simply adding a call to AsParallel(), we can specify that a collection should be processed in parallel.  This is simple, safe, and incredibly useful.

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  • How To Skip Commercials in Windows 7 Media Center

    - by DigitalGeekery
    If you use Windows 7 Media Center to record live TV, you’re probably interested in skipping through commercials. After all, a big reason to record programs is to avoid commercials, right? Today we focus on a fairly simple and free way to get you skipping commercials in no time. In Windows 7, the .wtv file format has replaced the dvr-ms file format used in previous versions of Media Center for Recorded TV. The .wtv file format, however, does not work very well with commercial skipping applications.  The Process Our first step will be to convert the recorded .wtv files to the previously used dvr-ms file format. This conversion will be done automatically by WtvWatcher. It’s important to note that this process deletes the original .wtv file after successfully converting to .dvr-ms. Next, we will use DVRMSToolBox with the DTB Addin to handle commercials skipping. This process does not “cut” or remove the commercials from the file. It merely skips the commercials during playback. WtvWatcher Download and install the WTVWatcher (link below). To install WtvWatcher, you’ll need to have Windows Installer 3.1 and .NET Framework 3.5 SP1. If you get the Publisher cannot be verified warning you can go ahead and click Install. We’ve completely tested this app and it contains no malware and runs successfully.   After installing, the WtvWatcher will pop up in the lower right corner of your screen. You will need to set the path to your Recorded TV directory. Click on the button for “Click here to set your recorded TV path…”   The WtvWatcher Preferences window will open…   …and you’ll be prompted to browse for your Recorded TV folder. If you did not change the default location at setup, it will be found at C:\Users\Public\Recorded TV. Click “OK” when finished. Click the “X” to close the Preferences screen. You should now see WtvWatcher begin to convert any existing WTV files.   The process should only take a few minutes per file. Note: If WtvWatcher detects an error during the conversion process, it will not delete the original WTV file.    You will probably want to run WtvWatcher on startup. This will allow WtvWatcher too constantly scan for new .wtv files to convert. There is no setting in the application to run on startup, so you’ll need to copy the WTV icon from your desktop into your Windows start menu “Startup” directory. To do so, click on Start > All Programs, right-click on Startup and click on Open all users. Drag and drop, or cut and paste, the WtvWatcher desktop shortcut into the Startup folder. DVRMSToolBox and DTBAddIn Next, we need to download and install the DVRMSToolBox and the DTBAddIn. These two pieces of software will do the actual commercial skipping. After downloading the DVRMSToolBox zip file, extract it and double-click the setup.exe file.  Click “Next” to begin the installation.   Unless DVRMSToolBox will only be used by Administrator accounts, check the “Modify File Permissions” box. Click “Next.” When you get to the Optional Components window, uncheck Download/Install ShowAnalyzer. We will not be using that application. When the installation is complete, click “Close.”    Next we need to install the DTBAddin. Unzip the download folder and run the appropriate .msi file for your system. It is available in 32 & 64 bit versions. Just double click on the file and take the default options. Click “Finish” when the install is completed. You will then be prompted to restart your computer. After your computer has restarted, open DVRMSToolBox settings by going to Start > All Programs, DVRMSToolBox, and click on DVRMStoMPEGSettings. On the MC Addin tab, make sure that Skip Commercials is checked. It should be by default.   On the Commercial Skip tab, make sure the Auto Skip option is selected. Click “Save.”   If you try to watch recorded TV before the file conversion and commercial indexing process is complete you’ll get the following message pop up in Media Center. If you click Yes, it will start indexing the commercials if WtvWatcher has already converted it to dvr-ms. Now you’re ready to kick back and watch your recorded tv without having to wait through those long commercial breaks. Conclusion The DVRMSToolBox is a powerful and complex application with a multitude of features and utilities. We’ve showed you a quick and easy way to get your Windows Media Center setup to skip commercials. This setup, like virtually all commercial skipping setups, is not perfect. You will occasionally find a commercial that doesn’t get skipped. Need help getting your Windows 7 PC configured for TV? Check out our previous tutorial on setting up live TV in Windows Media Center. Links Download WTV Watcher Download DVRMSToolBox Download DTBAddin Similar Articles Productive Geek Tips Using Netflix Watchnow in Windows Vista Media Center (Gmedia)Increase Skip and Replay Intervals in Windows 7 Media CenterSchedule Updates for Windows Media CenterIntegrate Hulu Desktop and Windows Media Center in Windows 7Add Color Coding to Windows 7 Media Center Program Guide TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 PCmover Professional Make your Joomla & Drupal Sites Mobile with OSMOBI Integrate Twitter and Delicious and Make Life Easier Design Your Web Pages Using the Golden Ratio Worldwide Growth of the Internet How to Find Your Mac Address Use My TextTools to Edit and Organize Text

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  • Scott Guthrie in Glasgow

    - by Martin Hinshelwood
    Last week Scott Guthrie was in Glasgow for his new Guathon tour, which was a roaring success. Scott did talks on the new features in Visual Studio 2010, Silverlight 4, ASP.NET MVC 2 and Windows Phone 7. Scott talked from 10am till 4pm, so this can only contain what I remember and I am sure lots of things he discussed just went in one ear and out another, however I have tried to capture at least all of my Ohh’s and Ahh’s. Visual Studio 2010 Right now you can download and install Visual Studio 2010 Candidate Release, but soon we will have the final product in our hands. With it there are some amazing improvements, and not just in the IDE. New versions of VB and C# come out of the box as well as Silverlight 4 and SharePoint 2010 integration. The new Intellisense features allow inline support for Types and Dictionaries as well as being able to type just part of a name and have the list filter accordingly. Even better, and my personal favourite is one that Scott did not mention, and that is that it is not case sensitive so I can actually find things in C# with its reasonless case sensitivity (Scott, can we please have an option to turn that off.) Another nice feature is the Routing engine that was created for ASP.NET MVC is now available for WebForms which is good news for all those that just imported the MVC DLL’s to get at it anyway. Another fantastic feature that will need some exploring is the ability to add validation rules to your entities and have them validated automatically on the front end. This removes the need to add your own validators and means that you can control an objects validation rules from a single location, the object. A simple command “GridView.EnableDynamicData(gettype(product))“ will enable this feature on controls. What was not clear was wither there would be support for this in WPF and WinForms as well. If there is, we can write our validation rules once and use everywhere. I was disappointed to here that there would be no inbuilt support for the Dynamic Language Runtime (DLR) with VS2010, but I think it will be there for .vNext. Because I have been concentrating on the Visual Studio ALM enhancements to VS2010 I found this section invaluable as I now know at least some of what I missed. Silverlight 4 I am not a big fan of Silverlight. There I said it, and I will probably get lynched for it. My big problem with Silverlight is that most of the really useful things I leaned from WPF do not work. I am only going to mention one thing and that is “x:Type”. If you are a WPF developer you will know how much power these 6 little letters provide; the ability to target templates at object types being the the most magical and useful. But, and this is a massive but, if you are developing applications that MUST run on platforms other than windows then Silverlight is your only choice (well that and Flash, but lets just not go there). And Silverlight has a huge install base as well.. 60% of all internet connected devices have Silverlight. Can Adobe say that? Even though I am not a fan of it my current project is a Silverlight one. If you start your XAML experience with Silverlight you will not be disappointed and neither will the users of the applications you build. Scott showed us a fantastic application called “Silverface” that is a Silverlight 4 Out of Browser application. I have looked for a link and can’t find one, but true to form, here is a fantastic WPF version called Fish Bowl from Microsoft. ASP.NET MVC 2 ASP.NET MVC is something I have played with but never used in anger. It is definitely the way forward, but WebForms is not dead yet. there are still circumstances when WebForms are better. If you are starting from greenfield and you are using TDD, then MVC is ultimately the only way you can go. New in version 2 are Dynamic Scaffolding helpers that let you control how data is presented in the UI from the Entities. Adding validation rules and other options that make sense there can help improve the overall ease of developing the UI. Also the Microsoft team have heard the cries of help from the larger site builders and provided “Areas” which allow a level of categorisation to your Controllers and Views. These work just like add-ins and have their own folder, but also have sub Controllers and Views. Areas are totally pluggable and can be dropped onto existing sites giving the ability to have boxed products in MVC, although what you do with all of those views is anyone's guess. They have been listening to everyone again with the new option to encapsulate UI using the Html.Action or Html.ActionRender. This uses the existing  .ascx functionality in ASP.NET to render partial views to the screen in certain areas. While this was possible before, it makes the method official thereby opening it up to the masses and making it a standard. At the end of the session Scott pulled out some IIS goodies including the IIS SEO Toolkit which can be used to verify your own site is “good” for search engine consumption. Better yet he suggested that you run it against your friends sites and shame them with how bad they are. note: make sure you have fixed yours first. Windows Phone 7 Series I had already seen the new UI for WP7 and heard about the developer story, but Scott brought that home by building a twitter application in about 20 minutes using the emulator. Scott’s only mistake was loading @plip’s tweets into the app… And guess what, it was written in Silverlight. When Windows Phone 7 launches you will be able to use about 90% of the codebase of your existing Silverlight application and use it on the phone! There are two downsides to the new WP7 architecture: No, your existing application WILL NOT work without being converted to either a Silverlight or XNA UI. NO, you will not be able to get your applications onto the phone any other way but through the Marketplace. Do I think these are problems? No, not even slightly. This phone is aimed at consumers who have probably never tried to install an application directly onto a device. There will be support for enterprise apps in the future, but for now enterprises should stay on Windows Phone 6.5.x devices. Post Event drinks At the after event drinks gathering Scott was checking out my HTC HD2 (released to the US this month on T-Mobile) and liked the Windows Phone 6.5.5 build I have on it. We discussed why Microsoft were not going to allow Windows Phone 7 Series onto it with my understanding being that it had 5 buttons and not 3, while Scott was sure that there was more to it from a hardware standpoint. I think he is right, and although the HTC HD2 has a DX9 compatible processor, it was never built with WP7 in mind. However, as if by magic Saturday brought fantastic news for all those that have already bought an HD2: Yes, this appears to be Windows Phone 7 running on a HTC HD2. The HD2 itself won't be getting an official upgrade to Windows Phone 7 Series, so all eyes are on the ROM chefs at the moment. The rather massive photos have been posted by Tom Codon on HTCPedia and they've apparently got WiFi, GPS, Bluetooth and other bits working. The ROM isn't online yet but according to the post there's a beta version coming soon. Leigh Geary - http://www.coolsmartphone.com/news5648.html  What was Scott working on on his flight back to the US?   Technorati Tags: VS2010,MVC2,WP7S,WP7 Follow: @CAMURPHY, @ColinMackay, @plip and of course @ScottGu

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  • Preserving Permalinks

    - by Daniel Moth
    One of the things that gets me on a rant is websites that break permalinks. If you have posted something somewhere and there is a public URL pointing to it, that URL should never ever return a 404. You are breaking all websites that ever linked to you and you are breaking all search engine links to your content (that others will try and follow). It is a pet peeve of mine. So when I had to move my blog, obviously I would preserve the root URL (www.danielmoth.com/Blog/), but I also wanted to preserve every URL my blog has generated over the years. To be clear, our focus here is on the URL formatting, not the content migration which I'll talk about in my next post. In this post, I'll describe my solution first and then what it solves. 1. The IIS7 Rewrite Module and web.config There are a few ways you can map an old URL to a new one (so when requests to the old URL come in, they get redirected to the new one). The new blog engine I use (dasBlog) has built-in functionality to do that (Scott refers to it here). Instead, the way I chose to address the issue was to use the IIS7 rewrite module. The IIS7 rewrite module allows redirecting URLs based on pattern matching, regular expressions and, of course, hardcoded full URLs for things that don't fall into any pattern. You can configure it visually from IIS Manager using a handy dialog that allows testing patterns against input URLs. Here is what mine looked like after configuring a few rules: To learn more about this technology check out this video, the reference page and this overview blog post; all 3 pages have a collection of related resources at the bottom worth checking out too. All the visual configuration ends up in a web.config file at the root folder of your website. If you are on a shared hosting service, probably the only way you can use the Rewrite Module is by directly editing the web.config file. Next, I'll describe the URLs I had to map and how that manifested itself in the web.config file. What I did was create the rules locally using the GUI, and then took the generated web.config file and uploaded it to my live site. You can view my web.config here. 2. Monthly Archives Observe the difference between the way the two blog engines generate this type of URL Blogger: /Blog/2004_07_01_mothblog_archive.html dasBlog: /Blog/default,month,2004-07.aspx In my web.config file, the rule that deals with this is the one named "monthlyarchive_redirect". 3. Categories Observe the difference between the way the two blog engines generate this type of URL Blogger: /Blog/labels/Personal.html dasBlog: /Blog/CategoryView,category,Personal.aspx In my web.config file the rule that deals with this is the one named "category_redirect". 4. Posts Observe the difference between the way the two blog engines generate this type of URL Blogger: /Blog/2004/07/hello-world.html dasBlog: /Blog/Hello-World.aspx In my web.config file the rule that deals with this is the one named "post_redirect". Note: The decision is taken to use dasBlog URLs that do not include the date info (see the description of my Appearance settings). If we included the date info then it would have to include the day part, which blogger did not generate. This makes it impossible to redirect correctly and to have a single permalink for blog posts moving forward. An implication of this decision, is that no two blog posts can have the same title. The tool I will describe in my next post (inelegantly) deals with duplicates, but not with triplicates or higher. 5. Unhandled by a generic rule Unfortunately, the two blog engines use different rules for generating URLs for blog posts. Most of the time the conversion is as simple as the example of the previous section where a post titled "Hello World" generates a URL with the words separated by a hyphen. Some times that is not the case, for example: /Blog/2006/05/medc-wrap-up.html /Blog/MEDC-Wrapup.aspx or /Blog/2005/01/best-of-moth-2004.html /Blog/Best-Of-The-Moth-2004.aspx or /Blog/2004/11/more-windows-mobile-2005-details.html /Blog/More-Windows-Mobile-2005-Details-Emerge.aspx In short, blogger does not add words to the title beyond ~39 characters, it drops some words from the title generation (e.g. a, an, on, the), and it preserve hyphens that appear in the title. For this reason, we need to detect these and explicitly list them for redirects (no regular expression can help here because the full set of rules is not listed anywhere). In my web.config file the rule that deals with this is the one named "Redirect rule1 for FullRedirects" combined with the rewriteMap named "StaticRedirects". Note: The tool I describe in my next post will detect all the URLs that need to be explicitly redirected and will list them in a file ready for you to copy them to your web.config rewriteMap. 6. C# code doing the same as the web.config I wrote some naive code that does the same thing as the web.config: given a string it will return a new string converted according to the 3 rules above. It does not take into account the 4th case where an explicit hard-coded conversion is needed (the tool I present in the next post does take that into account). static string REGEX_post_redirect = "[0-9]{4}/[0-9]{2}/([0-9a-z-]+).html"; static string REGEX_category_redirect = "labels/([_0-9a-z-% ]+).html"; static string REGEX_monthlyarchive_redirect = "([0-9]{4})_([0-9]{2})_[0-9]{2}_mothblog_archive.html"; static string Redirect(string oldUrl) { GroupCollection g; if (RunRegExOnIt(oldUrl, REGEX_post_redirect, 2, out g)) return string.Concat(g[1].Value, ".aspx"); if (RunRegExOnIt(oldUrl, REGEX_category_redirect, 2, out g)) return string.Concat("CategoryView,category,", g[1].Value, ".aspx"); if (RunRegExOnIt(oldUrl, REGEX_monthlyarchive_redirect, 3, out g)) return string.Concat("default,month,", g[1].Value, "-", g[2], ".aspx"); return string.Empty; } static bool RunRegExOnIt(string toRegEx, string pattern, int groupCount, out GroupCollection g) { if (pattern.Length == 0) { g = null; return false; } g = new Regex(pattern, RegexOptions.IgnoreCase | RegexOptions.Compiled).Match(toRegEx).Groups; return (g.Count == groupCount); } Comments about this post welcome at the original blog.

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  • Using a "white list" for extracting terms for Text Mining

    - by [email protected]
    In Part 1 of my post on "Generating cluster names from a document clustering model" (part 1, part 2, part 3), I showed how to build a clustering model from text documents using Oracle Data Miner, which automates preparing data for text mining. In this process we specified a custom stoplist and lexer and relied on Oracle Text to identify important terms.  However, there is an alternative approach, the white list, which uses a thesaurus object with the Oracle Text CTXRULE index to allow you to specify the important terms. INTRODUCTIONA stoplist is used to exclude, i.e., black list, specific words in your documents from being indexed. For example, words like a, if, and, or, and but normally add no value when text mining. Other words can also be excluded if they do not help to differentiate documents, e.g., the word Oracle is ubiquitous in the Oracle product literature. One problem with stoplists is determining which words to specify. This usually requires inspecting the terms that are extracted, manually identifying which ones you don't want, and then re-indexing the documents to determine if you missed any. Since a corpus of documents could contain thousands of words, this could be a tedious exercise. Moreover, since every word is considered as an individual token, a term excluded in one context may be needed to help identify a term in another context. For example, in our Oracle product literature example, the words "Oracle Data Mining" taken individually are not particular helpful. The term "Oracle" may be found in nearly all documents, as with the term "Data." The term "Mining" is more unique, but could also refer to the Mining industry. If we exclude "Oracle" and "Data" by specifying them in the stoplist, we lose valuable information. But it we include them, they may introduce too much noise. Still, when you have a broad vocabulary or don't have a list of specific terms of interest, you rely on the text engine to identify important terms, often by computing the term frequency - inverse document frequency metric. (This is effectively a weight associated with each term indicating its relative importance in a document within a collection of documents. We'll revisit this later.) The results using this technique is often quite valuable. As noted above, an alternative to the subtractive nature of the stoplist is to specify a white list, or a list of terms--perhaps multi-word--that we want to extract and use for data mining. The obvious downside to this approach is the need to specify the set of terms of interest. However, this may not be as daunting a task as it seems. For example, in a given domain (Oracle product literature), there is often a recognized glossary, or a list of keywords and phrases (Oracle product names, industry names, product categories, etc.). Being able to identify multi-word terms, e.g., "Oracle Data Mining" or "Customer Relationship Management" as a single token can greatly increase the quality of the data mining results. The remainder of this post and subsequent posts will focus on how to produce a dataset that contains white list terms, suitable for mining. CREATING A WHITE LIST We'll leverage the thesaurus capability of Oracle Text. Using a thesaurus, we create a set of rules that are in effect our mapping from single and multi-word terms to the tokens used to represent those terms. For example, "Oracle Data Mining" becomes "ORACLEDATAMINING." First, we'll create and populate a mapping table called my_term_token_map. All text has been converted to upper case and values in the TERM column are intended to be mapped to the token in the TOKEN column. TERM                                TOKEN DATA MINING                         DATAMINING ORACLE DATA MINING                  ORACLEDATAMINING 11G                                 ORACLE11G JAVA                                JAVA CRM                                 CRM CUSTOMER RELATIONSHIP MANAGEMENT    CRM ... Next, we'll create a thesaurus object my_thesaurus and a rules table my_thesaurus_rules: CTX_THES.CREATE_THESAURUS('my_thesaurus', FALSE); CREATE TABLE my_thesaurus_rules (main_term     VARCHAR2(100),                                  query_string  VARCHAR2(400)); We next populate the thesaurus object and rules table using the term token map. A cursor is defined over my_term_token_map. As we iterate over  the rows, we insert a synonym relationship 'SYN' into the thesaurus. We also insert into the table my_thesaurus_rules the main term, and the corresponding query string, which specifies synonyms for the token in the thesaurus. DECLARE   cursor c2 is     select token, term     from my_term_token_map; BEGIN   for r_c2 in c2 loop     CTX_THES.CREATE_RELATION('my_thesaurus',r_c2.token,'SYN',r_c2.term);     EXECUTE IMMEDIATE 'insert into my_thesaurus_rules values                        (:1,''SYN(' || r_c2.token || ', my_thesaurus)'')'     using r_c2.token;   end loop; END; We are effectively inserting the token to return and the corresponding query that will look up synonyms in our thesaurus into the my_thesaurus_rules table, for example:     'ORACLEDATAMINING'        SYN ('ORACLEDATAMINING', my_thesaurus)At this point, we create a CTXRULE index on the my_thesaurus_rules table: create index my_thesaurus_rules_idx on        my_thesaurus_rules(query_string)        indextype is ctxsys.ctxrule; In my next post, this index will be used to extract the tokens that match each of the rules specified. We'll then compute the tf-idf weights for each of the terms and create a nested table suitable for mining.

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  • CodePlex Daily Summary for Monday, June 14, 2010

    CodePlex Daily Summary for Monday, June 14, 2010New ProjectsBD File Hash: BD File Hash is a convenient file hash and hash compare tool for Windows which currently works with MD5, SHA-1, and SHA-256 algorithms. FileScan: This is an application that searches through a drive or directory structure for files matching a filter. This project was converted from VB to ...genesis9: genesis9HeinanOS: HeinanOS is an operating system developed mainly in C++. HeinanOS is a light OS (1.44 MB image) with a lot of capabilites and many more are being ...MediaBrowserWS - Creates a Web Service for the popular MediaBrowser plugin: Creates a web service in Media Center for accessing your MediaBrowser collection. Allows for external devices (Tablets/phones/laptops) to access a ...MME: New Edition of Managed Menu Extensions for Visual Studio 2010 The Main goal of "MME" is to provide easy access to adding Right Click menus in the ...MVMMapper: Generate the ViewModel and its mapping to the Model when implementing MVVM in .NET. Developed using T4 templates. Current version supports Silver...ProjectArDotNet: Si te agarro te parto! Si te agarro te emperno no me importa que seas menor de edad!Scriptagility for DotNetNuke: Scriptagility is a DotNetNuke module for Javascript developers. This module provides dynamic client scripting infrastructure for developing javascr...simpleLinux Distro: SimpleLinux. is a Linux distributions that is easy to use. Simple Linux website: http://simplelinux.tkTag Cloud Control for asp.net: Tag Cloud Control for asp.net allows the user to display the most important keywords to display in tag cloud. Each Tag has it own navigation url to...thefreeimdb: fsadie qwUppityUp: UppityUp is a simple and light-weight tray application which monitors a remote server and shows a notification when it comes online. This is usefu...Vivid3D 2 - DirectX 10 3D ToolKit: The sequel to my first ever engine wrote several years ago. It is not based on it in anyway. VSIDev: VSI DevXTQXK_WORK: Actionscript 3.0东坡博客: 这是一个ASP。net mvc 2博客。New Releases.NET Extensions - Extension Methods Library: Release 2010.08: Added extension methods for Bitmap manipulation (scaling for now): - Bitmap.ScaleToSize() - Bitmap.ScaleToSizeProportional() - Bitmap.ScaleProport...Black Falcon Software's Database Data-Access-Layers: “SQLHELPER”, “ORAHELPER” - Handling Binary Data: See attached document...BTech Networking Library: BTech Networking Library: Same as pervious just new namespace, extended networking coming soon!!!Community Forums NNTP bridge: Community Forums NNTP Bridge V37: Release of the Community Forums NNTP Bridge to access the social and anwsers MS forums with a single, open source NNTP bridge. This release has ad...Generic Entity Model 2: GEM2 build 54383: This is second BETA release of GEM2! Please see source code change sets for updates! Following implementation is not included in this release: My...Hades: Projet Hadès - Official Demo - Version 0.1.0 Beta: ---------------------------------------------------------------------------- - Projet Hadès - Official Demo - Version 0.1.0 Beta ------------------...HeinanOS: HeinanOS M1 Source Code: You can download HeinanOS M1 Source Code and contribute to HeinanOS development! Be aware that you should not use this code for your own systems! ...HeinanOS: Milestone 1: This is the first major release for HeinanOS 1.0 Please note this is a PRE-RELEASE! This release includes the following features: -Bootable DOS-...HKGolden Express: HKGoldenExpress (Build 201006131900): New features: (None) Bug fix: Incorrect message submit date of message/ replies. (Note: Showing message submit date is enabled since Build 20100...HKGolden Express: HKGoldenExpress (Build 201006140110): New features: (None) Bug fix: (None) Improvements: (None) Other changes: Set time zone of message date as Hong Kong. Adjusted the format of messa...MediaCoder.NET: MediaCoder.NET v1.0 Beta 1.5: Installer file for MediaCoder.NET v1.0 beta 1.5. Now converts multiple files.MME: First release: Features of this release 1. One installer MME.msi. However you can also install MMEMenuManagerSetup.vsix which installs a project template that e...MSBuild Launch Pad (mPad): 1.1 Beta 1: Platform selection box is added.MVMMapper: MVMMapper Release v 1.0.1: This release has no downloadable documentation. Please use the Documentation section to get started.NginxTray: NginxTray 0.7 RC2: NginxTray 0.7 RC2PowerAuras: PowerAuras-3.0.0K-beta3: New Auras: Item Name Equipment Slot Tracking Changes from beta1 5 new aura textures Fixed Tracking bug Added graphical equipment slot sele...PowerAuras: PowerAuras-3.0.0K-beta4: New Auras: Item Name Equipment Slot Tracking Changes from beta1 5 new aura textures Fixed Tracking bug Added graphical equipment slot sele...Scriptagility for DotNetNuke: Scriptagility 1.0 (Beta): Initial public release please evaluate and feedbackSharpDevelop: SharpDevelop 4.0 Beta 1: Release notes: http://community.sharpdevelop.net/forums/t/11388.aspxsimpleLinux Distro: Project X3: This is an example of download for simpleLinuxSOAPI - StackOverflow API Parser/Wrapper Generator: SOAPI Beta 3: The SOAPI Beta 3 download will be made availabe later today when the initial documentation is complete. The previously available Beta 1 download h...Sofa: Initial release V1.0: This is the first release of Sofa. As it is made of code being previously used, as we tested it is a stable release. But bugs are always possible,...Tag Cloud Control for asp.net: Tag Cloud Control for asp.net: Tag Cloud Control for asp.net allows the user to display the most important keywords to display in tag cloud. Each Tag has it own navigation url to...UppityUp: UppityUp v0.1: First functional version, supports monitoring availability by ping (ICMP) requests. Fit for general use. Consists of one standalone .exe file - no...VCC: Latest build, v2.1.30613.0: Automatic drop of latest buildWindStyle ExifInfo for Windows Live Writer: 1.1.0.0: Add: Multiple Language(English and Simplified Chinese); Add: Insert multiple files; Fix: Error when insert pictures without Exif info; Update: Icon...Work Recorder - Hold on own time!: WorkRecorder 1.2: +Add a whole day chartXsltDb - DotNetNuke Module Builder: 01.01.24: Syntax highlighting delivered!New samples for RadControls. On single page you can find RadTreeView, RadRating, RadChart, RadFormDecorator, RadEdito...xUnit.net Contrib: xunitcontrib 0.4 (ReSharper 5.0 RTM + dotCover): xunitcontrib release 0.4 (ReSharper runner) This release provides a test runner plugin for Resharper 5.0, 4.5 and 4.1, targetting all versions of x...Most Popular ProjectsCommunity Forums NNTP bridgeRIA Services EssentialsNeatUploadBxf (Basic XAML Framework)Agile Personal Development Methodology.NET Transactional File ManagerSOLID by exampleASP.NET MVC Time PlannerWEI ShareSiverlight ProjectMost Active ProjectsjQuery Library for SharePoint Web Servicespatterns & practices – Enterprise LibraryNB_Store - Free DotNetNuke Ecommerce Catalog ModuleRhyduino - Arduino and Managed CodeCommunity Forums NNTP bridgeCassandraemonBlogEngine.NETLightweight Fluent WorkflowMediaCoder.NETAndrew's XNA Helpers

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  • C#/.NET Little Pitfalls: The Dangers of Casting Boxed Values

    - by James Michael Hare
    Starting a new series to parallel the Little Wonders series.  In this series, I will examine some of the small pitfalls that can occasionally trip up developers. Introduction: Of Casts and Conversions What happens when we try to assign from an int and a double and vice-versa? 1: double pi = 3.14; 2: int theAnswer = 42; 3:  4: // implicit widening conversion, compiles! 5: double doubleAnswer = theAnswer; 6:  7: // implicit narrowing conversion, compiler error! 8: int intPi = pi; As you can see from the comments above, a conversion from a value type where there is no potential data loss is can be done with an implicit conversion.  However, when converting from one value type to another may result in a loss of data, you must make the conversion explicit so the compiler knows you accept this risk.  That is why the conversion from double to int will not compile with an implicit conversion, we can make the conversion explicit by adding a cast: 1: // explicit narrowing conversion using a cast, compiler 2: // succeeds, but results may have data loss: 3: int intPi = (int)pi; So for value types, the conversions (implicit and explicit) both convert the original value to a new value of the given type.  With widening and narrowing references, however, this is not the case.  Converting reference types is a bit different from converting value types.  First of all when you perform a widening or narrowing you don’t really convert the instance of the object, you just convert the reference itself to the wider or narrower reference type, but both the original and new reference type both refer back to the same object. Secondly, widening and narrowing for reference types refers the going down and up the class hierarchy instead of referring to precision as in value types.  That is, a narrowing conversion for a reference type means you are going down the class hierarchy (for example from Shape to Square) whereas a widening conversion means you are going up the class hierarchy (from Square to Shape).  1: var square = new Square(); 2:  3: // implicitly convers because all squares are shapes 4: // (that is, all subclasses can be referenced by a superclass reference) 5: Shape myShape = square; 6:  7: // implicit conversion not possible, not all shapes are squares! 8: // (that is, not all superclasses can be referenced by a subclass reference) 9: Square mySquare = (Square) myShape; So we had to cast the Shape back to Square because at that point the compiler has no way of knowing until runtime whether the Shape in question is truly a Square.  But, because the compiler knows that it’s possible for a Shape to be a Square, it will compile.  However, if the object referenced by myShape is not truly a Square at runtime, you will get an invalid cast exception. Of course, there are other forms of conversions as well such as user-specified conversions and helper class conversions which are beyond the scope of this post.  The main thing we want to focus on is this seemingly innocuous casting method of widening and narrowing conversions that we come to depend on every day and, in some cases, can bite us if we don’t fully understand what is going on!  The Pitfall: Conversions on Boxed Value Types Can Fail What if you saw the following code and – knowing nothing else – you were asked if it was legal or not, what would you think: 1: // assuming x is defined above this and this 2: // assignment is syntactically legal. 3: x = 3.14; 4:  5: // convert 3.14 to int. 6: int truncated = (int)x; You may think that since x is obviously a double (can’t be a float) because 3.14 is a double literal, but this is inaccurate.  Our x could also be dynamic and this would work as well, or there could be user-defined conversions in play.  But there is another, even simpler option that can often bite us: what if x is object? 1: object x; 2:  3: x = 3.14; 4:  5: int truncated = (int) x; On the surface, this seems fine.  We have a double and we place it into an object which can be done implicitly through boxing (no cast) because all types inherit from object.  Then we cast it to int.  This theoretically should be possible because we know we can explicitly convert a double to an int through a conversion process which involves truncation. But here’s the pitfall: when casting an object to another type, we are casting a reference type, not a value type!  This means that it will attempt to see at runtime if the value boxed and referred to by x is of type int or derived from type int.  Since it obviously isn’t (it’s a double after all) we get an invalid cast exception! Now, you may say this looks awfully contrived, but in truth we can run into this a lot if we’re not careful.  Consider using an IDataReader to read from a database, and then attempting to select a result row of a particular column type: 1: using (var connection = new SqlConnection("some connection string")) 2: using (var command = new SqlCommand("select * from employee", connection)) 3: using (var reader = command.ExecuteReader()) 4: { 5: while (reader.Read()) 6: { 7: // if the salary is not an int32 in the SQL database, this is an error! 8: // doesn't matter if short, long, double, float, reader [] returns object! 9: total += (int) reader["annual_salary"]; 10: } 11: } Notice that since the reader indexer returns object, if we attempt to convert using a cast to a type, we have to make darn sure we use the true, actual type or this will fail!  If the SQL database column is a double, float, short, etc this will fail at runtime with an invalid cast exception because it attempts to convert the object reference! So, how do you get around this?  There are two ways, you could first cast the object to its actual type (double), and then do a narrowing cast to on the value to int.  Or you could use a helper class like Convert which analyzes the actual run-time type and will perform a conversion as long as the type implements IConvertible. 1: object x; 2:  3: x = 3.14; 4:  5: // if you want to cast, must cast out of object to double, then 6: // cast convert. 7: int truncated = (int)(double) x; 8:  9: // or you can call a helper class like Convert which examines runtime 10: // type of the value being converted 11: int anotherTruncated = Convert.ToInt32(x); Summary You should always be careful when performing a conversion cast from values boxed in object that you are actually casting to the true type (or a sub-type). Since casting from object is a widening of the reference, be careful that you either know the exact, explicit type you expect to be held in the object, or instead avoid the cast and use a helper class to perform a safe conversion to the type you desire. Technorati Tags: C#,.NET,Pitfalls,Little Pitfalls,BlackRabbitCoder

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  • Using Table-Valued Parameters in SQL Server

    - by Jesse
    I work with stored procedures in SQL Server pretty frequently and have often found myself with a need to pass in a list of values at run-time. Quite often this list contains a set of ids on which the stored procedure needs to operate the size and contents of which are not known at design time. In the past I’ve taken the collection of ids (which are usually integers), converted them to a string representation where each value is separated by a comma and passed that string into a VARCHAR parameter of a stored procedure. The body of the stored procedure would then need to parse that string into a table variable which could be easily consumed with set-based logic within the rest of the stored procedure. This approach works pretty well but the VARCHAR variable has always felt like an un-wanted “middle man” in this scenario. Of course, I could use a BULK INSERT operation to load the list of ids into a temporary table that the stored procedure could use, but that approach seems heavy-handed in situations where the list of values is usually going to contain only a few dozen values. Fortunately SQL Server 2008 introduced the concept of table-valued parameters which effectively eliminates the need for the clumsy middle man VARCHAR parameter. Example: Customer Transaction Summary Report Let’s say we have a report that can summarize the the transactions that we’ve conducted with customers over a period of time. The report returns a pretty simple dataset containing one row per customer with some key metrics about how much business that customer has conducted over the date range for which the report is being run. Sometimes the report is run for a single customer, sometimes it’s run for all customers, and sometimes it’s run for a handful of customers (i.e. a salesman runs it for the customers that fall into his sales territory). This report can be invoked from a website on-demand, or it can be scheduled for periodic delivery to certain users via SQL Server Reporting Services. Because the report can be created from different places and the query to generate the report is complex it’s been packed into a stored procedure that accepts three parameters: @startDate – The beginning of the date range for which the report should be run. @endDate – The end of the date range for which the report should be run. @customerIds – The customer Ids for which the report should be run. Obviously, the @startDate and @endDate parameters are DATETIME variables. The @customerIds parameter, however, needs to contain a list of the identity values (primary key) from the Customers table representing the customers that were selected for this particular run of the report. In prior versions of SQL Server we might have made this parameter a VARCHAR variable, but with SQL Server 2008 we can make it into a table-valued parameter. Defining And Using The Table Type In order to use a table-valued parameter, we first need to tell SQL Server about what the table will look like. We do this by creating a user defined type. For the purposes of this stored procedure we need a very simple type to model a table variable with a single integer column. We can create a generic type called ‘IntegerListTableType’ like this: CREATE TYPE IntegerListTableType AS TABLE (Value INT NOT NULL) Once defined, we can use this new type to define the @customerIds parameter in the signature of our stored procedure. The parameter list for the stored procedure definition might look like: 1: CREATE PROCEDURE dbo.rpt_CustomerTransactionSummary 2: @starDate datetime, 3: @endDate datetime, 4: @customerIds IntegerListTableTableType READONLY   Note the ‘READONLY’ statement following the declaration of the @customerIds parameter. SQL Server requires any table-valued parameter be marked as ‘READONLY’ and no DML (INSERT/UPDATE/DELETE) statements can be performed on a table-valued parameter within the routine in which it’s used. Aside from the DML restriction, however, you can do pretty much anything with a table-valued parameter as you could with a normal TABLE variable. With the user defined type and stored procedure defined as above, we could invoke like this: 1: DECLARE @cusomterIdList IntegerListTableType 2: INSERT @customerIdList VALUES (1) 3: INSERT @customerIdList VALUES (2) 4: INSERT @customerIdList VALUES (3) 5:  6: EXEC dbo.rpt_CustomerTransationSummary 7: @startDate = '2012-05-01', 8: @endDate = '2012-06-01' 9: @customerIds = @customerIdList   Note that we can simply declare a variable of type ‘IntegerListTableType’ just like any other normal variable and insert values into it just like a TABLE variable. We could also populate the variable with a SELECT … INTO or INSERT … SELECT statement if desired. Using The Table-Valued Parameter With ADO .NET Invoking a stored procedure with a table-valued parameter from ADO .NET is as simple as building a DataTable and passing it in as the Value of a SqlParameter. Here’s some example code for how we would construct the SqlParameter for the @customerIds parameter in our stored procedure: 1: var customerIdsParameter = new SqlParameter(); 2: customerIdParameter.Direction = ParameterDirection.Input; 3: customerIdParameter.TypeName = "IntegerListTableType"; 4: customerIdParameter.Value = selectedCustomerIds.ToIntegerListDataTable("Value");   All we’re doing here is new’ing up an instance of SqlParameter, setting the pamameters direction, specifying the name of the User Defined Type that this parameter uses, and setting its value. We’re assuming here that we have an IEnumerable<int> variable called ‘selectedCustomerIds’ containing all of the customer Ids for which the report should be run. The ‘ToIntegerListDataTable’ method is an extension method of the IEnumerable<int> type that looks like this: 1: public static DataTable ToIntegerListDataTable(this IEnumerable<int> intValues, string columnName) 2: { 3: var intergerListDataTable = new DataTable(); 4: intergerListDataTable.Columns.Add(columnName); 5: foreach(var intValue in intValues) 6: { 7: var nextRow = intergerListDataTable.NewRow(); 8: nextRow[columnName] = intValue; 9: intergerListDataTable.Rows.Add(nextRow); 10: } 11:  12: return intergerListDataTable; 13: }   Since the ‘IntegerListTableType’ has a single int column called ‘Value’, we pass that in for the ‘columnName’ parameter to the extension method. The method creates a new single-columned DataTable using the provided column name then iterates over the items in the IEnumerable<int> instance adding one row for each value. We can then use this SqlParameter instance when invoking the stored procedure just like we would use any other parameter. Advanced Functionality Using passing a list of integers into a stored procedure is a very simple usage scenario for the table-valued parameters feature, but I’ve found that it covers the majority of situations where I’ve needed to pass a collection of data for use in a query at run-time. I should note that BULK INSERT feature still makes sense for passing large amounts of data to SQL Server for processing. MSDN seems to suggest that 1000 rows of data is the tipping point where the overhead of a BULK INSERT operation can pay dividends. I should also note here that table-valued parameters can be used to deal with more complex data structures than single-columned tables of integers. A User Defined Type that backs a table-valued parameter can use things like identities and computed columns. That said, using some of these more advanced features might require the use the SqlDataRecord and SqlMetaData classes instead of a simple DataTable. Erland Sommarskog has a great article on his website that describes when and how to use these classes for table-valued parameters. What About Reporting Services? Earlier in the post I referenced the fact that our example stored procedure would be called from both a web application and a SQL Server Reporting Services report. Unfortunately, using table-valued parameters from SSRS reports can be a bit tricky and warrants its own blog post which I’ll be putting together and posting sometime in the near future.

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  • Documenting C# Library using GhostDoc and SandCastle

    - by sreejukg
    Documentation is an essential part of any IT project, especially when you are creating reusable components that will be used by other developers (such as class libraries). Without documentation re-using a class library is almost impossible. Just think of coding .net applications without MSDN documentation (Ooops I can’t think of it). Normally developers, who know the bits and pieces of their classes, see this as a boring work to write details again to generate the documentation. Also the amount of work to make this and manage it changes made the process of manual creation of Documentation impossible or tedious. So what is the effective solution? Let me divide this into two steps 1. Generate comments for your code while you are writing the code. 2. Create documentation file using these comments. Now I am going to examine these processes. Step 1: Generate XML Comments automatically Most of the developers write comments for their code. The best thing is that the comments will be entered during the development process. Additionally comments give a good reference to the code, make your code more manageable/readable. Later these comments can be converted into documentation, along with your source code by identifying properties and methods I found an add-in for visual studio, GhostDoc that automatically generates XML documentation comments for C#. The add-in is available in Visual Studio Gallery at MSDN. You can download this from the url http://visualstudiogallery.msdn.microsoft.com/en-us/46A20578-F0D5-4B1E-B55D-F001A6345748. I downloaded the free version from the above url. The free version suits my requirement. There is a professional version (you need to pay some $ for this) available that gives you some more features. I found the free version itself suits my requirements. The installation process is straight forward. A couple of clicks will do the work for you. The best thing with GhostDoc is that it supports multiple versions of visual studio such as 2005, 2008 and 2010. After Installing GhostDoc, when you start Visual studio, the GhostDoc configuration dialog will appear. The first screen asks you to assign a hot key, pressing this hotkey will enter the comment to your code file with the necessary structure required by GhostDoc. Click Assign to go to the next step where you configure the rules for generating the documentation from the code file. Click Create to start creating the rules. Click finish button to close this wizard. Now you performed the necessary configuration required by GhostDoc. Now In Visual Studio tools menu you can find the GhostDoc that gives you some options. Now let us examine how GhostDoc generate comments for a method. I have write the below code in my code behind file. public Char GetChar(string str, int pos) { return str[pos]; } Now I need to generate the comments for this function. Select the function and enter the hot key assigned during the configuration. GhostDoc will generate the comments as follows. /// <summary> /// Gets the char. /// </summary> /// <param name="str">The STR.</param> /// <param name="pos">The pos.</param> /// <returns></returns> public Char GetChar(string str, int pos) { return str[pos]; } So this is a very handy tool that helps developers writing comments easily. You can generate the xml documentation file separately while compiling the project. This will be done by the C# compiler. You can enable the xml documentation creation option (checkbox) under Project properties -> Build tab. Now when you compile, the xml file will created under the bin folder. Step 2: Generate the documentation from the XML file Now you have generated the xml file documentation. Sandcastle is the tool from Microsoft that generates MSDN style documentation from the compiler produced XML file. The project is available in codeplex http://sandcastle.codeplex.com/. Download and install Sandcastle to your computer. Sandcastle is a command line tool that doesn’t have a rich GUI. If you want to automate the documentation generation, definitely you will be using the command line tools. Since I want to generate the documentation from the xml file generated in the previous step, I was expecting a GUI where I can see the options. There is a GUI available for Sandcastle called Sandcastle Help File Builder. See the link to the project in codeplex. http://www.codeplex.com/wikipage?ProjectName=SHFB. You need to install Sandcastle and then the Sandcastle Help file builder. From here I assume that you have installed both sandcastle and Sandcastle help file builder successfully. Once you installed the help file builder, it will be available in your all programs list. Click on the Sandcastle Help File Builder GUI, will launch application. First you need to create a project. Click on File -> New project The New project dialog will appear. Choose a folder to store your project file and give a name for your documentation project. Click the save button. Now you will see your project properties. Now from the Project explorer, right click on the Documentation Sources, Click on the Add Documentation Source link. A documentation source is a file such as an assembly or a Visual Studio solution or project from which information will be extracted to produce API documentation. From the Add Documentation source dialog, I have selected the XML file generated by my project. Once you add the xml file to the project, you will see the dll file automatically added by the help file builder. Now click on the build button. Now the application will generate the help file. The Build window gives to the result of each steps. Once the process completed successfully, you will have the following output in the build window. Now navigate to your Help Project (I have selected the folder My Documents\Documentation), inside help folder, you can find the chm file. Open the chm file will give you MSDN like documentation. Documentation is an important part of development life cycle. Sandcastle with GhostDoc make this process easier so that developers can implement the documentation in the projects with simple to use steps.

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  • SQL SERVER – Weekly Series – Memory Lane – #048

    - by Pinal Dave
    Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Order of Result Set of SELECT Statement on Clustered Indexed Table When ORDER BY is Not Used Above theory is true in most of the cases. However SQL Server does not use that logic when returning the resultset. SQL Server always returns the resultset which it can return fastest.In most of the cases the resultset which can be returned fastest is the resultset which is returned using clustered index. Effect of TRANSACTION on Local Variable – After ROLLBACK and After COMMIT One of the Jr. Developer asked me this question (What will be the Effect of TRANSACTION on Local Variable – After ROLLBACK and After COMMIT?) while I was rushing to an important meeting. I was getting late so I asked him to talk with his Application Tech Lead. When I came back from meeting both of them were looking for me. They said they are confused. I quickly wrote down following example for them. 2008 SQL SERVER – Guidelines and Coding Standards Complete List Download Coding standards and guidelines are very important for any developer on the path of a successful career. A coding standard is a set of guidelines, rules and regulations on how to write code. Coding standards should be flexible enough or should take care of the situation where they should not prevent best practices for coding. They are basically the guidelines that one should follow for better understanding. Download Guidelines and Coding Standards complete List Download Get Answer in Float When Dividing of Two Integer Many times we have requirements of some calculations amongst different fields in Tables. One of the software developers here was trying to calculate some fields having integer values and divide it which gave incorrect results in integer where accurate results including decimals was expected. Puzzle – Computed Columns Datatype Explanation SQL Server automatically does a cast to the data type having the highest precedence. So the result of INT and INT will be INT, but INT and FLOAT will be FLOAT because FLOAT has a higher precedence. If you want a different data type, you need to do an EXPLICIT cast. Renaming SP is Not Good Idea – Renaming Stored Procedure Does Not Update sys.procedures I have written many articles about renaming a tables, columns and procedures SQL SERVER – How to Rename a Column Name or Table Name, here I found something interesting about renaming the stored procedures and felt like sharing it with you all. The interesting fact is that when we rename a stored procedure using SP_Rename command, the Stored Procedure is successfully renamed. But when we try to test the procedure using sp_helptext, the procedure will be having the old name instead of new names. 2009 Insert Values of Stored Procedure in Table – Use Table Valued Function It is clear from the result set that , where I have converted stored procedure logic into the table valued function, is much better in terms of logic as it saves a large number of operations. However, this option should be used carefully. The performance of the stored procedure is “usually” better than that of functions. Interesting Observation – Index on Index View Used in Similar Query Recently, I was working on an optimization project for one of the largest organizations. While working on one of the queries, we came across a very interesting observation. We found that there was a query on the base table and when the query was run, it used the index, which did not exist in the base table. On careful examination, we found that the query was using the index that was on another view. This was very interesting as I have personally never experienced a scenario like this. In simple words, “Query on the base table can use the index created on the indexed view of the same base table.” Interesting Observation – Execution Plan and Results of Aggregate Concatenation Queries Working with SQL Server has never seemed to be monotonous – no matter how long one has worked with it. Quite often, I come across some excellent comments that I feel like acknowledging them as blog posts. Recently, I wrote an article on SQL SERVER – Execution Plan and Results of Aggregate Concatenation Queries Depend Upon Expression Location, which is well received in the community. 2010 I encourage all of you to go through complete series and write your own on the subject. If you write an article and send it to me, I will publish it on this blog with due credit to you. If you write on your own blog, I will update this blog post pointing to your blog post. SQL SERVER – ORDER BY Does Not Work – Limitation of the View 1 SQL SERVER – Adding Column is Expensive by Joining Table Outside View – Limitation of the View 2 SQL SERVER – Index Created on View not Used Often – Limitation of the View 3 SQL SERVER – SELECT * and Adding Column Issue in View – Limitation of the View 4 SQL SERVER – COUNT(*) Not Allowed but COUNT_BIG(*) Allowed – Limitation of the View 5 SQL SERVER – UNION Not Allowed but OR Allowed in Index View – Limitation of the View 6 SQL SERVER – Cross Database Queries Not Allowed in Indexed View – Limitation of the View 7 SQL SERVER – Outer Join Not Allowed in Indexed Views – Limitation of the View 8 SQL SERVER – SELF JOIN Not Allowed in Indexed View – Limitation of the View 9 SQL SERVER – Keywords View Definition Must Not Contain for Indexed View – Limitation of the View 10 SQL SERVER – View Over the View Not Possible with Index View – Limitations of the View 11 2011 Startup Parameters Easy to Configure If you are a regular reader of this blog, you must be aware that I have written about SQL Server Denali recently. Here is the quickest way to reach into the screen where we can change the startup parameters. Go to SQL Server Configuration Manager >> SQL Server Services >> Right Click on the Server >> Properties >> Startup Parameters 2012 Validating Unique Columnname Across Whole Database I sometimes come across very strange requirements and often I do not receive a proper explanation of the same. Here is the one of those examples. For example “Our business requirement is when we add new column we want it unique across current database.” Read the solution to this strange request in this blog post. Excel Losing Decimal Values When Value Pasted from SSMS ResultSet It is very common when users are coping the resultset to Excel, the floating point or decimals are missed. The solution is very much simple and it requires a small adjustment in the Excel. By default Excel is very smart and when it detects the value which is getting pasted is numeric it changes the column format to accommodate that. Basic Calculation and PEMDAS Order of Operation Read this interesting blog post for fantastic conversation about the subject. Copy Column Headers from Resultset – SQL in Sixty Seconds #027 – Video http://www.youtube.com/watch?v=x_-3tLqTRv0 Delete From Multiple Table – Update Multiple Table in Single Statement There are two questions which I get every single day multiple times. In my gmail, I have created standard canned reply for them. Let us see the questions here. I want to delete from multiple table in a single statement how will I do it? I want to update multiple table in a single statement how will I do it? Read the answer in the blog post. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Responsive Inline Elements with Twitter Bootstrap

    - by MightyZot
    Originally posted on: http://geekswithblogs.net/MightyZot/archive/2013/11/12/responsive-inline-elements-with-twitter-bootstrap.aspxTwitter Boostrap is a responsive css platform created by some dudes affiliated with Twitter and since supported and maintained by an open source following. I absolutely love the new version of this css toolkit. They rebuilt it with a mobile first strategy and it’s very easy to layout pages once you get the hang of it. Using a css / javascript framework like bootstrap is certainly much easier than coding your layout by hand. And, you get a “leg up” when it comes to adding responsive features to your site. Bootstrap includes column layout classes that let you specify size and placement based upon the viewport width. In addition, there are a handful of responsive helpers to hide and show content based upon the user’s device size. Most notably, the visible-xs, visible-sm, visible-md, and visible-lg classes let you show content for devices corresponding to those sizes (they are listed in the bootstrap docs.) hidden-xs, hidden-sm, hidden-md, and hidden-lg let you hide content for devices with those respective sizes. These helpers work great for showing and hiding block elements. Unfortunately, there isn’t a provision yet in Twitter Bootstrap (as of the time of this writing) for inline elements. We are using the navbar classes to create a navigation bar at the top of our website, www.crowdit.com. When you shrink the width of the screen to tablet or phone size, the tools in the navbar are turned into a drop down menu, and a button appears on the right side of the navbar. This is great! But, we wanted different content to display based upon whether the items were on the navbar versus when they were in the dropdown menu. The visible-?? and hidden-?? classes make this easy for images and block elements. In our case, we wanted our anchors to show different text depending upon whether they’re in the navbar, or in the dropdown. span is inherently inline and it can be a block element. My first approach was to create two anchors for each options, one set visible when the navbar is on a desktop or laptop with a wide display and another set visible when the elements converted to a dropdown menu. That works fine with the visible-?? and hidden-?? classes, but it just doesn’t seem that clean to me. I put up with that for about a week…last night I created the following classes to augment the block-based classes provided by bootstrap. .cdt-hidden-xs, .cdt-hidden-sm, .cdt-hidden-md, .cdt-hidden-lg {     display: inline !important; } @media (max-width:767px) {     .cdt-hidden-xs, .cdt-hidden-sm.cdt-hidden-xs, .cdt-hidden-md.cdt-hidden-xs, .cdt-hidden-lg.cdt-hidden-xs {         display: none !important;     } } @media (min-width:768px) and (max-width:991px) {     .cdt-hidden-xs.cdt-hidden-sm, .cdt-hidden-sm, .cdt-hidden-md.cdt-hidden-sm, .cdt-hidden-lg.cdt-hidden-sm {         display: none !important;     } } @media (min-width:992px) and (max-width:1199px) {     .cdt-hidden-xs.cdt-hidden-md, .cdt-hidden-sm.cdt-hidden-md, .cdt-hidden-md, .cdt-hidden-lg.cdt-hidden-md {         display: none !important;     } } @media (min-width:1200px) {     .cdt-hidden-xs.cdt-hidden-lg, .cdt-hidden-sm.cdt-hidden-lg, .cdt-hidden-md.cdt-hidden-lg, .cdt-hidden-lg {         display: none !important;     } } .cdt-visible-xs, .cdt-visible-sm, .cdt-visible-md, .cdt-visible-lg {     display: none !important; } @media (max-width:767px) {     .cdt-visible-xs, .cdt-visible-sm.cdt-visible-xs, .cdt-visible-md.cdt-visible-xs, .cdt-visible-lg.cdt-visible-xs {         display: inline !important;     } } @media (min-width:768px) and (max-width:991px) {     .cdt-visible-xs.cdt-visible-sm, .cdt-visible-sm, .cdt-visible-md.cdt-visible-sm, .cdt-visible-lg.cdt-visible-sm {         display: inline !important;     } } @media (min-width:992px) and (max-width:1199px) {     .cdt-visible-xs.cdt-visible-md, .cdt-visible-sm.cdt-visible-md, .cdt-visible-md, .cdt-visible-lg.cdt-visible-md {         display: inline !important;     } } @media (min-width:1200px) {     .cdt-visible-xs.cdt-visible-lg, .cdt-visible-sm.cdt-visible-lg, .cdt-visible-md.cdt-visible-lg, .cdt-visible-lg {         display: inline !important;     } } I created these by looking at the example provided by bootstrap and consolidating the styles. “cdt” is just a prefix that I’m using to distinguish these classes from the block-based classes in bootstrap. You are welcome to change the prefix to whatever feels right for you. These classes can be applied to spans in textual content to hide and show text based upon the browser width. Applying the styles is simple… <span class=”cdt-visible-xs”>This text is visible in extra small</span> <span class=”cdt-visible-sm”>This text is visible in small</span> Why would you want to do this? Here are a couple of examples, shown in screen shots. This is the CrowdIt navbar on larger displays. Notice how the text is two line and certain words are capitalized? Now, check this out! Here is a screen shot showing the dropdown menu that’s displayed when the browser window is tablet or phone sized. The markup to make this happen is quite simple…take a look. <li>     <a href="@Url.Action("what-is-crowdit","home")" title="Learn about what CrowdIt can do for your Small Business">         <span class="cdt-hidden-xs">WHAT<br /><small>is CrowdIt?</small></span>         <span class="cdt-visible-xs">What is CrowdIt?</span>     </a> </li> There is a single anchor tag in this example and only the spans change visibility based on browser width. I left them separate for readability and because I wanted to use the small tag; however, you could just as easily hide the “WHAT” and the br tag on small displays and replace them with “What “, consolidating this even further to text containing a single span. <span class=”cdt-hidden-xs”>WHAT<br /></span><span class=”cdt-visible-xs”>What </span>is CrowdIt? You might be a master of css and have a better method of handling this problem. If so, I’d love to hear about your solution…leave me some feedback! You’ll be entered into a drawing for a chance to win an autographed picture of ME! Yay!

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  • SQL SERVER – Weekly Series – Memory Lane – #052

    - by Pinal Dave
    Let us continue with the final episode of the Memory Lane Series. Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Set Server Level FILLFACTOR Using T-SQL Script Specifies a percentage that indicates how full the Database Engine should make the leaf level of each index page during index creation or alteration. fillfactor must be an integer value from 1 to 100. The default is 0. Limitation of Online Index Rebuld Operation Online operation means when online operations are happening in the database are in normal operational condition, the processes which are participating in online operations does not require exclusive access to the database. Get Permissions of My Username / Userlogin on Server / Database A few days ago, I was invited to one of the largest database company. I was asked to review database schema and propose changes to it. There was special username or user logic was created for me, so I can review their database. I was very much interested to know what kind of permissions I was assigned per server level and database level. I did not feel like asking Sr. DBA the question about permissions. Simple Example of WHILE Loop With CONTINUE and BREAK Keywords This question is one of those questions which is very simple and most of the users get it correct, however few users find it confusing for the first time. I have tried to explain the usage of simple WHILE loop in the first example. BREAK keyword will exit the stop the while loop and control is moved to the next statement after the while loop. CONTINUE keyword skips all the statement after its execution and control is sent to the first statement of while loop. Forced Parameterization and Simple Parameterization – T-SQL and SSMS When the PARAMETERIZATION option is set to FORCED, any literal value that appears in a SELECT, INSERT, UPDATE or DELETE statement is converted to a parameter during query compilation. When the PARAMETERIZATION database option is SET to SIMPLE, the SQL Server query optimizer may choose to parameterize the queries. 2008 Transaction and Local Variables – Swap Variables – Update All At Once Concept Summary : Transaction have no effect over memory variables. When UPDATE statement is applied over any table (physical or memory) all the updates are applied at one time together when the statement is committed. First of all I suggest that you read the article listed above about the effect of transaction on local variant. As seen there local variables are independent of any transaction effect. Simulate INNER JOIN using LEFT JOIN statement – Performance Analysis Just a day ago, while I was working with JOINs I find one interesting observation, which has prompted me to create following example. Before we continue further let me make very clear that INNER JOIN should be used where it cannot be used and simulating INNER JOIN using any other JOINs will degrade the performance. If there are scopes to convert any OUTER JOIN to INNER JOIN it should be done with priority. 2009 Introduction to Business Intelligence – Important Terms & Definitions Business intelligence (BI) is a broad category of application programs and technologies for gathering, storing, analyzing, and providing access to data from various data sources, thus providing enterprise users with reliable and timely information and analysis for improved decision making. Difference Between Candidate Keys and Primary Key Candidate Key – A Candidate Key can be any column or a combination of columns that can qualify as unique key in database. There can be multiple Candidate Keys in one table. Each Candidate Key can qualify as Primary Key. Primary Key – A Primary Key is a column or a combination of columns that uniquely identify a record. Only one Candidate Key can be Primary Key. 2010 Taking Multiple Backup of Database in Single Command – Mirrored Database Backup I recently had a very interesting experience. In one of my recent consultancy works, I was told by our client that they are going to take the backup of the database and will also a copy of it at the same time. I expressed that it was surely possible if they were going to use a mirror command. In addition, they told me that whenever they take two copies of the database, the size of the database, is always reduced. Now this was something not clear to me, I said it was not possible and so I asked them to show me the script. Corrupted Backup File and Unsuccessful Restore The CTO, who was also present at the location, got very upset with this situation. He then asked when the last successful restore test was done. As expected, the answer was NEVER.There were no successful restore tests done before. During that time, I was present and I could clearly see the stress, confusion, carelessness and anger around me. I did not appreciate the feeling and I was pretty sure that no one in there wanted the atmosphere like me. 2011 TRACEWRITE – Wait Type – Wait Related to Buffer and Resolution SQL Trace is a SQL Server database engine technology which monitors specific events generated when various actions occur in the database engine. When any event is fired it goes through various stages as well various routes. One of the routes is Trace I/O Provider, which sends data to its final destination either as a file or rowset. DATEDIFF – Accuracy of Various Dateparts If you want to have accuracy in seconds, you need to use a different approach. In the first example, the accurate method is to find the number of seconds first and then divide it by 60 to convert it in minutes. Dedicated Access Control for SQL Server Express Edition http://www.youtube.com/watch?v=1k00z82u4OI Book Signing at SQLPASS 2012 Who I Am And How I Got Here – True Story as Blog Post If there was a shortcut to success – I want to know. I learnt SQL Server hard way and I am still learning. There are so many things, I have to learn. There is not enough time to learn everything which we want to learn. I am constantly working on it every day. I welcome you to join my journey as well. Please join me in my journey to learn SQL Server – more the merrier. Vacation, Travel and Study – A New Concept Even those who have advanced degrees and went to college for years, or even decades, find studying hard.  There is a difference between studying for a career and studying for a certification.  At least to get a degree there is a variety of subjects, with labs, exams, and practice problems to make things more interesting. Order By Numeric Values Formatted as String We have a table which has a column containing alphanumeric data. The data always has first as an integer and later part as a string. The business need is to order the data based on the first part of the alphanumeric data which is an integer. Now the problem is that no matter how we use ORDER BY the result is not produced as expected. Let us understand this with an example. Resolving SQL Server Connection Errors – SQL in Sixty Seconds #030 – Video One of the most famous errors related to SQL Server is about connecting to SQL Server itself. Here is how it goes, most of the time developers have worked with SQL Server and knows pretty much every error which they face during development language. However, hardly they install fresh SQL Server. As the installation of the SQL Server is a rare occasion unless you are a DBA who is responsible for such an instance – the error faced during installations are pretty rare as well. http://www.youtube.com/watch?v=1k00z82u4OI Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • C# Extension Methods - To Extend or Not To Extend...

    - by James Michael Hare
    I've been thinking a lot about extension methods lately, and I must admit I both love them and hate them. They are a lot like sugar, they taste so nice and sweet, but they'll rot your teeth if you eat them too much.   I can't deny that they aren't useful and very handy. One of the major components of the Shared Component library where I work is a set of useful extension methods. But, I also can't deny that they tend to be overused and abused to willy-nilly extend every living type.   So what constitutes a good extension method? Obviously, you can write an extension method for nearly anything whether it is a good idea or not. Many times, in fact, an idea seems like a good extension method but in retrospect really doesn't fit.   So what's the litmus test? To me, an extension method should be like in the movies when a person runs into their twin, separated at birth. You just know you're related. Obviously, that's hard to quantify, so let's try to put a few rules-of-thumb around them.   A good extension method should:     Apply to any possible instance of the type it extends.     Simplify logic and improve readability/maintainability.     Apply to the most specific type or interface applicable.     Be isolated in a namespace so that it does not pollute IntelliSense.     So let's look at a few examples in relation to these rules.   The first rule, to me, is the most important of all. Once again, it bears repeating, a good extension method should apply to all possible instances of the type it extends. It should feel like the long lost relative that should have been included in the original class but somehow was missing from the family tree.    Take this nifty little int extension, I saw this once in a blog and at first I really thought it was pretty cool, but then I started noticing a code smell I couldn't quite put my finger on. So let's look:       public static class IntExtensinos     {         public static int Seconds(int num)         {             return num * 1000;         }           public static int Minutes(int num)         {             return num * 60000;         }     }     This is so you could do things like:       ...     Thread.Sleep(5.Seconds());     ...     proxy.Timeout = 1.Minutes();     ...     Awww, you say, that's cute! Well, that's the problem, it's kitschy and it doesn't always apply (and incidentally you could achieve the same thing with TimeStamp.FromSeconds(5)). It's syntactical candy that looks cool, but tends to rot and pollute the code. It would allow things like:       total += numberOfTodaysOrders.Seconds();     which makes no sense and should never be allowed. The problem is you're applying an extension method to a logical domain, not a type domain. That is, the extension method Seconds() doesn't really apply to ALL ints, it applies to ints that are representative of time that you want to convert to milliseconds.    Do you see what I mean? The two problems, in a nutshell, are that a) Seconds() called off a non-time value makes no sense and b) calling Seconds() off something to pass to something that does not take milliseconds will be off by a factor of 1000 or worse.   Thus, in my mind, you should only ever have an extension method that applies to the whole domain of that type.   For example, this is one of my personal favorites:       public static bool IsBetween<T>(this T value, T low, T high)         where T : IComparable<T>     {         return value.CompareTo(low) >= 0 && value.CompareTo(high) <= 0;     }   This allows you to check if any IComparable<T> is within an upper and lower bound. Think of how many times you type something like:       if (response.Employee.Address.YearsAt >= 2         && response.Employee.Address.YearsAt <= 10)     {     ...     }     Now, you can instead type:       if(response.Employee.Address.YearsAt.IsBetween(2, 10))     {     ...     }     Note that this applies to all IComparable<T> -- that's ints, chars, strings, DateTime, etc -- and does not depend on any logical domain. In addition, it satisfies the second point and actually makes the code more readable and maintainable.   Let's look at the third point. In it we said that an extension method should fit the most specific interface or type possible. Now, I'm not saying if you have something that applies to enumerables, you create an extension for List, Array, Dictionary, etc (though you may have reasons for doing so), but that you should beware of making things TOO general.   For example, let's say we had an extension method like this:       public static T ConvertTo<T>(this object value)     {         return (T)Convert.ChangeType(value, typeof(T));     }         This lets you do more fluent conversions like:       double d = "5.0".ConvertTo<double>();     However, if you dig into Reflector (LOVE that tool) you will see that if the type you are calling on does not implement IConvertible, what you convert to MUST be the exact type or it will throw an InvalidCastException. Now this may or may not be what you want in this situation, and I leave that up to you. Things like this would fail:       object value = new Employee();     ...     // class cast exception because typeof(IEmployee) != typeof(Employee)     IEmployee emp = value.ConvertTo<IEmployee>();       Yes, that's a downfall of working with Convertible in general, but if you wanted your fluent interface to be more type-safe so that ConvertTo were only callable on IConvertibles (and let casting be a manual task), you could easily make it:         public static T ConvertTo<T>(this IConvertible value)     {         return (T)Convert.ChangeType(value, typeof(T));     }         This is what I mean by choosing the best type to extend. Consider that if we used the previous (object) version, every time we typed a dot ('.') on an instance we'd pull up ConvertTo() whether it was applicable or not. By filtering our extension method down to only valid types (those that implement IConvertible) we greatly reduce our IntelliSense pollution and apply a good level of compile-time correctness.   Now my fourth rule is just my general rule-of-thumb. Obviously, you can make extension methods as in-your-face as you want. I included all mine in my work libraries in its own sub-namespace, something akin to:       namespace Shared.Core.Extensions { ... }     This is in a library called Shared.Core, so just referencing the Core library doesn't pollute your IntelliSense, you have to actually do a using on Shared.Core.Extensions to bring the methods in. This is very similar to the way Microsoft puts its extension methods in System.Linq. This way, if you want 'em, you use the appropriate namespace. If you don't want 'em, they won't pollute your namespace.   To really make this work, however, that namespace should only include extension methods and subordinate types those extensions themselves may use. If you plant other useful classes in those namespaces, once a user includes it, they get all the extensions too.   Also, just as a personal preference, extension methods that aren't simply syntactical shortcuts, I like to put in a static utility class and then have extension methods for syntactical candy. For instance, I think it imaginable that any object could be converted to XML:       namespace Shared.Core     {         // A collection of XML Utility classes         public static class XmlUtility         {             ...             // Serialize an object into an xml string             public static string ToXml(object input)             {                 var xs = new XmlSerializer(input.GetType());                   // use new UTF8Encoding here, not Encoding.UTF8. The later includes                 // the BOM which screws up subsequent reads, the former does not.                 using (var memoryStream = new MemoryStream())                 using (var xmlTextWriter = new XmlTextWriter(memoryStream, new UTF8Encoding()))                 {                     xs.Serialize(xmlTextWriter, input);                     return Encoding.UTF8.GetString(memoryStream.ToArray());                 }             }             ...         }     }   I also wanted to be able to call this from an object like:       value.ToXml();     But here's the problem, if i made this an extension method from the start with that one little keyword "this", it would pop into IntelliSense for all objects which could be very polluting. Instead, I put the logic into a utility class so that users have the choice of whether or not they want to use it as just a class and not pollute IntelliSense, then in my extensions namespace, I add the syntactical candy:       namespace Shared.Core.Extensions     {         public static class XmlExtensions         {             public static string ToXml(this object value)             {                 return XmlUtility.ToXml(value);             }         }     }   So now it's the best of both worlds. On one hand, they can use the utility class if they don't want to pollute IntelliSense, and on the other hand they can include the Extensions namespace and use as an extension if they want. The neat thing is it also adheres to the Single Responsibility Principle. The XmlUtility is responsible for converting objects to XML, and the XmlExtensions is responsible for extending object's interface for ToXml().

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