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  • Converting ntext to nvcharmax(max) - Getting around size limitation

    - by Overflew
    Hi all, I'm trying to change an existing SQL NText column to nvcharmax(max), and encountering an error on the size limit. There's a large amount of existing data, some of which is more than the 8k limit, I believe. We're looking to convert this, so that the field is searchable in LINQ. The 2x SQL statements I've tried are: update Table set dataNVarChar = convert(nvarchar(max), dataNtext) where dataNtext is not null update Table set dataNVarChar = cast(dataNtext as nvarchar(max)) where dataNtext is not null And the error I get is: Cannot create a row of size 8086 which is greater than the allowable maximum row size of 8060. This is using SQL Server 2008. Any help appreciated, Thanks. Update / Solution: The marked answer below is correct, and SQL 2008 can change the column to the correct data type in my situation, and there are no dramas with the LINQ-utilising application we use on top of it: alter table [TBL] alter column [COL] nvarchar(max) I've also been advised to follow it up with: update [TBL] set [COL] = [COL] Which completes the conversion by moving the data from the lob structure to the table (if the length in less than 8k), which improves performance / keeps things proper.

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  • linux xorg dual different monitors mouse border

    - by Metiu
    If I hook an external monitor to my Linux laptop and configure it for dual head with the Gnome system tools, I do get them configured with the proper resolution and position (one to the left of the other) The mouse pointer, however, will apparently use the greatest of the two vertical resolutions. This way, when I move up to the top border, the mouse exits the visible screen, traveling in empty space, and this is quite annoying, because you can't go to the upper panel just by going up very fast. Is there a way of enforcing the right resolutions for the mouse, too? Thank you

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  • Jquery grid overlay in wordpress

    - by Anders Kitson
    I am adding this simple plugin that I have working in a static html site, and am trying to add it to a wordpress development site based off of 960 gs. The jquery code links are correct but the console gives me this error "Uncaught TypeError: Cannot call method 'addGrid' of null" I got the code from this turtorial http://www.badlydrawntoy.com/2009/04/21/960gs-grid-overlay-a-jquery-plugin/ Here is the code I am using /*<![CDATA[*/ // onload $(function() { $("body").addGrid(12, {img_path: 'img/'}); }); /*]]>*/ Here is the code for the plugin /* * @ description: Plugin to display 960.gs gridlines See http://960.gs/ * @author: badlyDrawnToy sharp / http://www.badlydrawntoy.com * @license: Creative Commons License - ShareAlike http://creativecommons.org/licenses/by-sa/3.0/ * @version: 1.0 20th April 2009 */ (function($){$.fn.addGrid=function(cols,options){var defaults={default_cols:12,z_index:999,img_path:'/images/',opacity:.6};var opts=$.extend(defaults,options);var cols=cols!=null&&(cols===12||cols===16)?cols:12;var cols=cols===opts.default_cols?'12_col':'16_col';return this.each(function(){var $el=$(this);var height=$el.height();var wrapper=$('<div id="'+opts.grid_id+'"/>').appendTo($el).css({'display':'none','position':'absolute','top':0,'z-index':(opts.z_index-1),'height':height,'opacity':opts.opacity,'width':'100%'});$('<div/>').addClass('container_12').css({'margin':'0 auto','width':'960px','height':height,'background-image':'url('+opts.img_path+cols+'.png)','background-repeat':'repeat-y'}).appendTo(wrapper);$('<div>grid on</div>').appendTo($el).css({'position':'absolute','top':0,'left':0,'z-index':opts.z_index,'background':'#222','color':'#fff','padding':'3px 6px','width':'40px','text-align':'center'}).hover(function(){$(this).css("cursor","pointer");},function(){$(this).css("cursor","default");}).toggle(function(){$(this).text("grid off");$('#'+opts.grid_id).slideDown();},function(){$(this).text("grid on");$('#'+opts.grid_id).slideUp();});});};})(jQuery);

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  • Generic ASP.NET MVC Route Conflict

    - by Donn Felker
    I'm working on a Legacy ASP.NET system. I say legacy because there are NO tests around 90% of the system. I'm trying to fix the routes in this project and I'm running into a issue I wish to solve with generic routes. I have the following routes: routes.MapRoute( "DefaultWithPdn", "{controller}/{action}/{pdn}", new { controller = "", action = "Index", pdn = "" }, null ); routes.MapRoute( "DefaultWithClientId", "{controller}/{action}/{clientId}", new { controller = "", action = "index", clientid = "" }, null ); The problem is that the first route is catching all of the traffic for what I need to be routed to the second route. The route is generic (no controller is defined in the constraint in either route definition) because multiple controllers throughout the entire app share this same premise (sometimes we need a "pdn" sometimes we need a "clientId"). How can I map these generic routes so that they go to the proper controller and action, yet not have one be too greedy? Or can I at all? Are these routes too generic (which is what I'm starting to believe is the case). My only option at this point (AFAIK) is one of the following: In the contraints, apply a regex to match the action values like: (foo|bar|biz|bang) and the same for the controller: (home|customer|products) for each controller. However, this has a problem in the fact that I may need to do this: ~/Foo/Home/123 // Should map to "DefaultwithPdn" ~/Foo/Home/abc // Should map to "DefaultWithClientId" Which means that if the Foo Controller has an action that takes a pdn and another action that takes a clientId (which happens all the time in this app), the wrong route is chosen. To hardcode these contstraints into each possible controller/action combo seems like a lot of duplication to me and I have the feeling I've been looking at the problem for too long so I need another pair of eyes to help out. Can I have generic routes to handle this scenario? Or do I need to have custom routes for each controller with constraints applied to the actions on those routes? Thanks

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  • Displaying NON-ASCII Characters using HttpClient

    - by Abdullah Gheith
    So, i am using this code to get the whole HTML of a website. But i dont seem to get non-ascii characters with me. all i get is diamonds with question mark. characters like this: å, appears like this: ? I doubt its because of the charset, what could it then be? Log.e("HTML", "henter htmlen.."); String url = "http://beep.tv2.dk"; HttpClient client = new DefaultHttpClient(); client.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1); client.getParams().setParameter(CoreProtocolPNames.HTTP_ELEMENT_CHARSET, "UTF-8"); HttpGet request = new HttpGet(url); HttpResponse response = client.execute(request); Header h = HeaderValueFormatter response.addHeader(header) String html = ""; InputStream in = response.getEntity().getContent(); BufferedReader reader = new BufferedReader(new InputStreamReader(in)); StringBuilder str = new StringBuilder(); String line = null; while((line = reader.readLine()) != null) { str.append(line); } in.close(); //b = false; html = str.toString();

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  • Optimizing an embedded SELECT query in mySQL

    - by Crazy Serb
    Ok, here's a query that I am running right now on a table that has 45,000 records and is 65MB in size... and is just about to get bigger and bigger (so I gotta think of the future performance as well here): SELECT count(payment_id) as signup_count, sum(amount) as signup_amount FROM payments p WHERE tm_completed BETWEEN '2009-05-01' AND '2009-05-30' AND completed > 0 AND tm_completed IS NOT NULL AND member_id NOT IN (SELECT p2.member_id FROM payments p2 WHERE p2.completed=1 AND p2.tm_completed < '2009-05-01' AND p2.tm_completed IS NOT NULL GROUP BY p2.member_id) And as you might or might not imagine - it chokes the mysql server to a standstill... What it does is - it simply pulls the number of new users who signed up, have at least one "completed" payment, tm_completed is not empty (as it is only populated for completed payments), and (the embedded Select) that member has never had a "completed" payment before - meaning he's a new member (just because the system does rebills and whatnot, and this is the only way to sort of differentiate between an existing member who just got rebilled and a new member who got billed for the first time). Now, is there any possible way to optimize this query to use less resources or something, and to stop taking my mysql resources down on their knees...? Am I missing any info to clarify this any further? Let me know... EDIT: Here are the indexes already on that table: PRIMARY PRIMARY 46757 payment_id member_id INDEX 23378 member_id payer_id INDEX 11689 payer_id coupon_id INDEX 1 coupon_id tm_added INDEX 46757 tm_added, product_id tm_completed INDEX 46757 tm_completed, product_id

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  • Passing optional parameter by reference in c++

    - by Moomin
    I'm having a problem with optional function parameter in C++ What I'm trying to do is to write function with optional parameter which is passed by reference, so that I can use it in two ways (1) and (2), but on (2) I don't really care what is the value of mFoobar. I've tried such a code: void foo(double &bar, double &foobar = NULL) { bar = 100; foobar = 150; } int main() { double mBar(0),mFoobar(0); foo(mBar,mFoobar); // (1) cout << mBar << mFoobar; mBar = 0; mFoobar = 0; foo(mBar); // (2) cout << mBar << mFoobar; return 0; } but it crashes at void foo(double &bar, double &foobar = NULL) with message : error: default argument for 'double& foobar' has type 'int' Is it possible to solve it without function overloading? Thanks in advance for any suggestions. Pawel

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  • odd nullreference error at foreach when rendering view

    - by giddy
    This error is so weird I Just can't really figure out what is really wrong! In UserController I have public virtual ActionResult Index() { var usersmdl = from u in RepositoryFactory.GetUserRepo().GetAll() select new UserViewModel { ID = u.ID, UserName = u.Username, UserGroupName = u.UserGroupMain.GroupName, BranchName = u.Branch.BranchName, Password = u.Password, Ace = u.ACE, CIF = u.CIF, PF = u.PF }; if (usersmdl != null) { return View(usersmdl.AsEnumerable()); } return View(); } My view is of type @model IEnumerable<UserViewModel> on the top. This is what happens: Where and what exactly IS null!? I create the users from a fake repository with moq. I also wrote unit tests, which pass, to ensure the right amount of mocked users are returned. Maybe someone can point me in the right direction here? Top of the stack trace is : at lambda_method(Closure , User ) at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext() at ASP.Index_cshtml.Execute() Is it something to do with linq here? Tell me If I should include the full stack trace.

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  • iTextSharp Overlay Image

    - by pennylane
    Hi guys I have an instance where I have a logo image as part of some artwork.. If a user uploads a new logo I have a form field which is larger than the default logo. I then use that form field to position the new image. The problem is I need to set the background colour of that form field to white so that it covers the old logo in the event that the new image is smaller than the old logo.. what I have done is: foreach (var imageField in imageReplacements) { fields.SetFieldProperty(imageField.Key, "bgcolor", iTextSharp.text.Color.WHITE, null); fields.RegenerateField(imageField.Key); PdfContentByte overContent = stamper.GetOverContent(imageField.Value.PageNumber); float[] logoArea = fields.GetFieldPositions(imageField.Key); if (logoArea != null) { iTextSharp.text.Rectangle logoRect = new iTextSharp.text.Rectangle(logoArea[1], logoArea[2], logoArea[3], logoArea[4]); var logo = iTextSharp.text.Image.GetInstance(imageField.Value.Location); if (logo.Width >= logoRect.Width || logo.Height >= logoRect.Height) { logo.ScaleToFit(logoRect.Width, logoRect.Height); } logo.Alignment = iTextSharp.text.Image.ALIGN_LEFT; logo.SetAbsolutePosition(logoRect.Left, logoArea[2] + (logoRect.Height - logo.ScaledHeight) / 2); // left: logoArea[3] - logo.ScaledWidth + (logoRect.Width - logo.ScaledWidth) / 2 overContent.AddImage(logo); } } The problem with this is that the background colour of the field is set to white and the image then doesn't appear.. i remove the SetFieldProperty and RegenerateField commands and the image replacement works fine.. is there a way to set a stacking order on layers?

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  • How can I simply change a class variable from another class in ObjectiveC?

    - by Daniel
    I simply want to change a variable of an object from another class. I can compile without a problem, but my variable always is set to 'null'. I used the following code: Object.h: @interface Object : NSObject { //... NSString *color; //... } @property(nonatomic, retain) NSString* color; + (id)Object; - (void)setColor:(NSString*)col; - (NSString*)getColor; @end Object.m: +(id)Object{ return [[[Object alloc] init] autorelease]; } - (void)setColor:(NSString*)col { self.color = col; } - (NSString*)getColor { return self.color; } MyViewController.h #import "Object.h" @interface ClassesTestViewController : UIViewController { Object *myObject; UILabel *label1; } @property UILabel *label1; @property (assign) Object *myObject; @end MyViewController.m: #import "Object.h" @implementation MyViewController @synthesize myObject; - (void)viewDidLoad { [myObject setColor:@"red"]; NSLog(@"Color = %@", [myObject getColor]); [super viewDidLoad]; } The NSLog message is always Color = (null) I tried many different ways to solve this problem, but no success. Any help would be appreciated.

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  • Java Compiler Creation Help..Please

    - by Brian
    I need some help with my code here...What we are trying to do is make a compiler that will read a file containing Machine Code and converting it to 100 lines of 4 bits example: this code is the machine code being converting to opcode and operands. I need some help please.. thanks 799 798 198 499 1008 1108 899 909 898 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Everything compiles but when I go and run my Test.java I get the following OutPut: Exception in thread "main" java.util.NoSuchElementException: No line found at java.util.Scanner.nextLine(Scanner.java:1516) at Compiler.FirstPass(Compiler.java:22) at Compiler.compile(Compiler.java:11) at Test.main(Test.java:5) Here is my class Compiler: import java.io.*; import java.io.DataOutputStream; import java.util.NoSuchElementException; import java.util.Scanner; class Compiler{ private int lc = 0; private int dc = 99; public void compile(String filename) { SymbolList symbolTable = FirstPass(filename); SecondPass(symbolTable, filename); } public SymbolList FirstPass(String filename) { File file = new File(filename); SymbolList temp = new SymbolList(); int dc = 99; int lc = 0; try{ Scanner scan = new Scanner(file); String line = scan.nextLine(); String[] linearray = line.split(" "); while(line!=null){ if(!linearray[0].equals("REM")){ if(!this.isInstruction(linearray[0])){ linearray[0]=removeColon(linearray[0]); if(this.isInstruction(linearray[1])){ temp.add(new Symbol(linearray[0], lc, null)); lc++; } else { temp.add(new Symbol(linearray[0], dc, Integer.valueOf((linearr\ ay[2])))); dc--; } } else { if(!linearray[0].equals("REM")) lc++; } } try{ line = scan.nextLine(); } catch(NoSuchElementException e){ line=null; break; } linearray = line.split(" "); } } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } return temp; } public String makeFilename(String filename) { return filename + ".ex"; } public String removeColon(String str) { if(str.charAt(str.length()-1) == ':'){ return str.substring(0, str.length()-1); } else { return str; } } public void SecondPass(SymbolList symbolTable, String filename){ try { int dc = 99; //Open file for reading File file = new File(filename); Scanner scan = new Scanner(file); //Make filename of new executable file String newfile = makeFilename(filename); //Open Output Stream for writing new file. FileOutputStream os = new FileOutputStream(filename); DataOutputStream dos = new DataOutputStream(os); //Read First line. Split line by Spaces into linearray. String line = scan.nextLine(); String[] linearray = line.split(" "); while(scan.hasNextLine()){ if(!linearray[0].equals("REM")){ int inst=0, opcode, loc; if(isInstruction(linearray[0])){ opcode = getOpcode(linearray[0]); loc = symbolTable.searchName(linearray[1]).getMemloc(); inst = (opcode*100)+loc; } else if(!isInstruction(linearray[0])){ if(isInstruction(linearray[1])){ opcode = getOpcode(linearray[1]); if(linearray[1].equals("STOP")) inst=0000; else { loc = symbolTable.searchName(linearray[2]).getMemloc(); inst = (opcode*100)+loc; } } if(linearray[1].equals("DC")) dc--; } System.out.println(inst); dos.writeInt(inst); linearray = line.split(" "); } if(scan.hasNextLine()) { line = scan.nextLine(); } } scan.close(); for(int i = lc; i <= dc; i++) { dos.writeInt(0); } for(int i = dc+1; i<100; i++){ dos.writeInt(symbolTable.searchLocation(i).getValue()); if(i!=99) dos.writeInt(0); } dos.close(); os.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } public int getOpcode(String inst){ int toreturn = -1; if(isInstruction(inst)){ if(inst.equals("STOP")) toreturn=0; if(inst.equals("LD")) toreturn=1; if(inst.equals("STO")) toreturn=2; if(inst.equals("ADD")) toreturn=3; if(inst.equals("SUB")) toreturn=4; if(inst.equals("MPY")) toreturn=5; if(inst.equals("DIV")) toreturn=6; if(inst.equals("IN")) toreturn=7; if(inst.equals("OUT")) toreturn=8; if(inst.equals("B")) toreturn=9; if(inst.equals("BGTR")) toreturn=10; if(inst.equals("BZ")) toreturn=11; return toreturn; } else { return -1; } } public boolean isInstruction(String totest){ boolean toreturn = false; String[] labels = {"IN", "LD", "SUB", "BGTR", "BZ", "OUT", "B", "STO", "STOP", "AD\ D", "MTY", "DIV"}; for(int i = 0; i < 12; i++){ if(totest.equals(labels[i])) toreturn = true; } return toreturn; } } And here is my class Computer: import java.io.*; import java.util.NoSuchElementException; import java.util.Scanner; class Computer{ private Cpu cpu; private Input in; private OutPut out; private Memory mem; public Computer() throws IOException { Memory mem = new Memory(100); Input in = new Input(); OutPut out = new OutPut(); Cpu cpu = new Cpu(); System.out.println(in.getInt()); } public void run() throws IOException { cpu.reset(); cpu.setMDR(mem.read(cpu.getMAR())); cpu.fetch2(); while (!cpu.stop()) { cpu.decode(); if (cpu.OutFlag()) OutPut.display(mem.read(cpu.getMAR())); if (cpu.InFlag()) mem.write(cpu.getMDR(),in.getInt()); if (cpu.StoreFlag()) { mem.write(cpu.getMAR(),in.getInt()); cpu.getMDR(); } else { cpu.setMDR(mem.read(cpu.getMAR())); cpu.execute(); cpu.fetch(); cpu.setMDR(mem.read(cpu.getMAR())); cpu.fetch2(); } } } public void load() { mem.loadMemory(); } } Here is my Memory class: import java.io.*; import java.util.NoSuchElementException; import java.util.Scanner; class Memory{ private MemEl[] memArray; private int size; private int[] mem; public Memory(int s) {size = s; memArray = new MemEl[s]; for(int i = 0; i < s; i++) memArray[i] = new MemEl(); } public void write (int loc,int val) {if (loc >=0 && loc < size) memArray[loc].write(val); else System.out.println("Index Not in Domain"); } public int read (int loc) {return memArray[loc].read(); } public void dump() { for(int i = 0; i < size; i++) if(i%1 == 0) System.out.println(memArray[i].read()); else System.out.print(memArray[i].read()); } public void writeTo(int location, int value) { mem[location] = value; } public int readFrom(int location) { return mem[location]; } public int size() { return mem.length; } public void loadMemory() { this.write(0, 799); this.write(1, 798); this.write(2, 198); this.write(3, 499); this.write(4, 1008); this.write(5, 1108); this.write(6, 899); this.write(7, 909); this.write(8, 898); this.write(9, 0000); } public void loadFromFile(String filename){ try { FileReader fr = new FileReader(filename); BufferedReader br = new BufferedReader(fr); String read=null; int towrite=0; int l=0; do{ try{ read=br.readLine(); towrite = Integer.parseInt(read); }catch(Exception e){ } this.write(l, towrite); l++; }while(l<100); }catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } Here is my Test class: public class Test{ public static void main(String[] args) throws java.io.IOException { Compiler compiler = new Compiler(); compiler.compile("program.txt"); } }

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  • help needed on libcurl programming in sending HTTP HEAD Request.

    - by Mani
    Hi all, I need clarifications on using libcurl for the following: I need to send an http HEAD request shown as below :: HEAD /mshare/3/30002:12:primary/stream_xNKNVH.mpeg HTTP/1.1 Host: 192.168.70.1:8080 Accept: */* User-Agent: Kreatel_IP-STB getcontentFeatures.dlna.org: 1 The code I wrote (shown below) , sends the HEAD Request in slightly different way: curl_global_init(CURL_GLOBAL_ALL); CURL* ctx = NULL; const char *url = "http://192.168.70.1:8080/mshare/3/30002:12:primary/stream_xNKNVH.mpeg" ; char *returnString; struct curl_slist *headers = NULL; ctx = curl_easy_init(); headers = curl_slist_append(headers,"Accept: */*"); headers = curl_slist_append(headers,"User-Agent: Kreatel_IP-STB");\ headers = curl_slist_append(headers,"getcontentFeatures.dlna.org: 1"); headers = curl_slist_append(headers,"Pragma:"); headers = curl_slist_append(headers,"Proxy-Connection:"); curl_easy_setopt(ctx,CURLOPT_HTTPHEADER , headers ); curl_easy_setopt(ctx,CURLOPT_NOBODY ,1 ); curl_easy_setopt(ctx,CURLOPT_VERBOSE, 1); curl_easy_setopt(ctx,CURLOPT_URL,url ); curl_easy_setopt(ctx,CURLOPT_NOPROGRESS ,1 ); curl_easy_perform(ctx); curl_easy_cleanup(ctx); curl_global_cleanup(); The code shown above sends the HEAD Request in slightly different form (shown below) HEAD http://192.168.70.1:8080/mshare/3/30002:12:primary/stream_xNKNVH.mpeg HTTP/1.1 Host: 192.168.70.1:8080 Proxy-Connection: Keep-Alive Accept: */* User-Agent: Kreatel_IP-STB getcontentFeatures.dlna.org: 1 Can any one , share the appropriate code ?

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  • Dynamic Auto updating (to UI, Grid) binding list in C# Winform?

    - by Dhana
    I'm not even sure if i'm doing this correctly. But basically I have a list of objects that are built out of a class/interface. From there, I am binding the list to a datagrid view that is on a Windows Form (C#) Here the list is a Sync list which will auto update the UI, in this case datagridview. Every thing works fine now, but now i would like to have the List should have an dynamic object, that is the object will have by default two static property (ID, Name), and at run time user will select remaining properties. These should be bind to the data grid. Any update on the list should be auto reflected in the grid. I am aware that, we can use dynamic objects, but i would like to know , how to approach for solution, datagridview.DataSource = myData; // myData is AutoUpdateList<IPersonInfo> Now IPersonInfo is the type of object, need to add dynamic properties for this type at runtime. public class AutoUpdateList<T> : System.ComponentModel.BindingList<T> { private System.ComponentModel.ISynchronizeInvoke _SyncObject; private System.Action<System.ComponentModel.ListChangedEventArgs> _FireEventAction; public AutoUpdateList() : this(null) { } public AutoUpdateList(System.ComponentModel.ISynchronizeInvoke syncObject) { _SyncObject = syncObject; _FireEventAction = FireEvent; } protected override void OnListChanged(System.ComponentModel.ListChangedEventArgs args) { try { if (_SyncObject == null) { FireEvent(args); } else { _SyncObject.Invoke(_FireEventAction, new object[] { args }); } } catch (Exception) { // TODO: Log Here } } private void FireEvent(System.ComponentModel.ListChangedEventArgs args) { base.OnListChanged(args); } } Could you help out on this?

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  • Explorer forgetting how to cut and paste files

    - by raimesh
    My Windows XP (SP3) machine (at work) occasionally "forgets" how to cut-and-paste files in Explorer - if I cut or copy a file then go to paste it elsewhere, the "paste" and "paste shortcut" menu items are greyed out. The keyboard shortcuts (Ctrl+X/Ctrl+C,Ctrl+V) don't work either, and neither does Drag-and-Drop - clicking and dragging a file/folder doesn't change the pointer and letting go doesn't drop the item anywhere. Restarting the explorer.exe process usually fixes the problem, but sometimes I need to do a full reboot. Note: this may be related to the following existing question, although that's Vista and it sounds like the asker has more permanent problems than I do: http://superuser.com/questions/27045/copy-paste-in-vista-explorer-broken-not-ms-vpc So, any idea what might be causing the problem and how to avoid it?

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  • Create new or update existing entity at one go with JPA

    - by Alex R
    A have a JPA entity that has timestamp field and is distinguished by a complex identifier field. What I need is to update timestamp in an entity that has already been stored, otherwise create and store new entity with the current timestamp. As it turns out the task is not as simple as it seems from the first sight. The problem is that in concurrent environment I get nasty "Unique index or primary key violation" exception. Here's my code: // Load existing entity, if any. Entity e = entityManager.find(Entity.class, id); if (e == null) { // Could not find entity with the specified id in the database, so create new one. e = entityManager.merge(new Entity(id)); } // Set current time... e.setTimestamp(new Date()); // ...and finally save entity. entityManager.flush(); Please note that in this example entity identifier is not generated on insert, it is known in advance. When two or more of threads run this block of code in parallel, they may simultaneously get null from entityManager.find(Entity.class, id) method call, so they will attempt to save two or more entities at the same time, with the same identifier resulting in error. I think that there are few solutions to the problem. Sure I could synchronize this code block with a global lock to prevent concurrent access to the database, but would it be the most efficient way? Some databases support very handy MERGE statement that updates existing or creates new row if none exists. But I doubt that OpenJPA (JPA implementation of my choice) supports it. Event if JPA does not support SQL MERGE, I can always fall back to plain old JDBC and do whatever I want with the database. But I don't want to leave comfortable API and mess with hairy JDBC+SQL combination. There is a magic trick to fix it using standard JPA API only, but I don't know it yet. Please help.

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  • Why is the compiler caching my "random" and NULLED variables?

    - by alex gray
    I am confounded by the fact that even using different programs (on the same machine) to run /compile, and after nilling the vaues (before and after) the function.. that NO MATTER WHAT.. I'll keep getting the SAME "random" numbers… each and every time I run it. I swear this is NOT how it's supposed to work.. I'm going to illustrate as simply as is possible… #import <Foundation/Foundation.h> int main(int argc, char *argv[]) { int rPrimitive = 0; rPrimitive = 1 + rand() % 50; NSNumber *rObject = nil; rObject = [NSNumber numberWithInt:rand() % 10]; NSLog(@"%i %@", rPrimitive, rObject); rPrimitive = 0; rObject = nil; NSLog(@"%i %@", rPrimitive, rObject); return 0; } Run it in TextMate: i686-apple-darwin11-llvm-gcc-4.2 8 9 0 (null) Run it in CodeRunner: i686-apple-darwin11-llvm-gcc-4.2 8 9 0 (null) Run it a million times, if you'd like. You can gues what it will always be. Why does this happen? Why oh why is this "how it is"?

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  • How can I improve the performance of LinqToSql queries that use EntitySet properties?

    - by DanM
    I'm using LinqToSql to query a small, simple SQL Server CE database. I've noticed that any operations involving sub-properties are disappointingly slow. For example, if I have a Customer table that is referenced by an Order table, LinqToSql will automatically create an EntitySet<Order> property. This is a nice convenience, allowing me to do things like Customer.Order.Where(o => o.ProductName = "Stopwatch"), but for some reason, SQL Server CE hangs up pretty bad when I try to do stuff like this. One of my queries, which isn't really that complicated takes 3-4 seconds to complete. I can get the speed up to acceptable, even fast, if I just grab the two tables individually and convert them to List<Customer> and List<Order>, then join then manually with my own query, but this is throwing out a lot of what makes LinqToSql so appealing. So, I'm wondering if I can somehow get the whole database into RAM and just query that way, then occasionally save it. Is this possible? How? If not, is there anything else I can do to boost the performance besides resorting to doing all the joins manually? Note: My database in its initial state is about 250K and I don't expect it to grow to more than 1-2Mb. So, loading the data into RAM certainly wouldn't be a problem from a memory point of view. Update Here are the table definitions for the example I used in my question: create table Order ( Id int identity(1, 1) primary key, ProductName ntext null ) create table Customer ( Id int identity(1, 1) primary key, OrderId int null references Order (Id) )

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  • Why is this linq extension method hit the database twice?

    - by Pure.Krome
    Hi folks, I have an extension method called ToListIfNotNullOrEmpty(), which is hitting the DB twice, instead of once. The first time it returns one result, the second time it returns all the correct results. I'm pretty sure the first time it hits the database, is when the .Any() method is getting called. here's the code. public static IList<T> ToListIfNotNullOrEmpty<T>(this IEnumerable<T> value) { if (value.IsNullOrEmpty()) { return null; } if (value is IList<T>) { return (value as IList<T>); } return new List<T>(value); } public static bool IsNullOrEmpty<T>(this IEnumerable<T> value) { if (value != null) { return !value.Any(); } return true; } I'm hoping to refactor it so that, before the .Any() method is called, it actually enumerates through the entire list. If i do the following, only one DB call is made, because the list is already enumerated. var pewPew = (from x in whatever select x) .ToList() // This enumerates. .ToListIsNotNullOrEmpty(); // This checks the enumerated result. I sorta don't really want to call ToList() then my extension method. Any ideas, folks?

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  • Ubuntu freezes when gdm starts showing userlist

    - by Enrique Becerra
    I have Ubuntu 10.10 (upgraded from 10.04) I was browsing in Firefox yesterday, then the PC did a suddenly reset Once I restarted, everything went normal until gdm begun showing. Then everything froze and locked when userlist showed. I could not move mouse pointer nor do anything with keyboard. Both, mouse and keyboard work fine, because this Ubuntu is dual-booting with a Windows XP install which loads/works fine. Here is my .xsession-errors file, but I don't have a clue what may be wrong. Thanks http://pastebin.com/GVtneEAF

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  • Linked List push()

    - by JKid314159
    The stack is initialized with a int MaxSize =3. Then I push one int onto the list. " Pushed:" is returned to the console. Program crashes here. I think my logic is flawed but unsure. Maybe an infinite loop or unmet condition? Thanks for your help. I'm trying to traverse the list to the last node in the second part of the full() method. I implemented this stack as array based so must implement this method full() as this method is inside of main class. while(!stacker.full()) { cout << "Enter number = "; cin >> intIn; stacker.push(intIn); cout << "Pushed: " << intIn << endl; }//while Call to LinkListStack.cpp to class LinkList full(). int LinkList::full() { if(head == NULL) { top = 0; } else { LinkNode * tmp1; LinkNode * tmp2; tmp1 = head; while(top != MaxSize) { if(tmp1->next != NULL){ tmp2 = tmp1->next; tmp1 = tmp2; ++top; }//if }//while }//else return (top + 1 == MaxSize); }

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  • Non-normalized association with legacy tables in Rails and ActiveRecord

    - by Thomas Holmström
    I am building a Rails application accessing a legacy system. The data model contains Customers which can have one or more Subscriptions. A Subscription always belong to one and only one Customer. Though not needed, this association is represented through a join table "subscribes", which do not have an id column: Column | Type | Modifiers -----------------+---------+----------- customer_id | integer | not null subscription_id | integer | not null I have this coded as a has_and_belongs_to_many declarations in both Customer and Subscription class Customer < Activerecord::Base has_and_belongs_to_many :subscriptions, :join_table => "subscribes", :foreign_key => "customer_id", :association_foreign_key => "subscription_id" end class Subscription < Activerecord::Base has_and_belongs_to_many :customers, :join_table => "subscribes", :foreign_key => "subscription_id", :association_foreign_key => "customer_id" end The problem I have is that there can only ever be one customer for each subscription, not many, and the join table will always contain at most one row with a certain customer_id. And thus, I don't want the association "customers" on a Subscription which returns an array of (at most one) Customer, I really do want the relation "customer" which returns the Customer associated. Is there any way to force ActiveRecord to make this a 1-to-N relation even though the join table itself seems to make it an N-to-M relation? --Thomas

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  • Two entities with @ManyToOne should join the same table

    - by Ivan Yatskevich
    I have the following entities Student @Entity public class Student implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } Teacher @Entity public class Teacher implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } Task @Entity public class Task implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @ManyToOne(optional = false) @JoinTable(name = "student_task", inverseJoinColumns = { @JoinColumn(name = "student_id") }) private Student author; @ManyToOne(optional = false) @JoinTable(name = "student_task", inverseJoinColumns = { @JoinColumn(name = "teacher_id") }) private Teacher curator; //getters and setters } Consider that author and curator are already stored in DB and both are in the attached state. I'm trying to persist my Task: Task task = new Task(); task.setAuthor(author); task.setCurator(curator); entityManager.persist(task); Hibernate executes the following SQL: insert into student_task (teacher_id, id) values (?, ?) which, of course, leads to null value in column "student_id" violates not-null constraint Can anyone explain this issue and possible ways to resolve it?

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  • Javascript Cookie Function not working for Domain

    - by danit
    Here are the functions Im using: Set Cookie: function set_cookie ( name, value, exp_y, exp_m, exp_d, path, domain, secure ) { var cookie_string = name + "=" + escape ( value ); if ( exp_y ) { var expires = new Date ( exp_y, exp_m, exp_d ); cookie_string += "; expires=" + expires.toGMTString(); } if ( path ) cookie_string += "; path=" + escape ( path ); if ( domain ) cookie_string += "; domain=" + escape ( domain ); if ( secure ) cookie_string += "; secure"; document.cookie = cookie_string; } Read Cookie: function get_cookie ( cookie_name ) { var results = document.cookie.match ( '(^|;) ?' + cookie_name + '=([^;]*)(;|$)' ); if ( results ) return ( unescape ( results[2] ) ); else return null; } Delete Cookie: function delete_cookie ( cookie_name ) { var cookie_date = new Date ( ); // current date & time cookie_date.setTime ( cookie_date.getTime() - 1 ); document.cookie = cookie_name += "=; expires=" + cookie_date.toGMTString(); } The Jquery I use to construct the cookie: if(get_cookie('visible')== 'no') { $("#wrapper").hide(); $(".help").hide(); $("#slid .show").show(); $("#slid .hide").hide(); } else { $("#slid .show").hide(); $("#slid .hide").show(); } $("#slider").click(function() { if(get_cookie('visible')== null) { set_cookie('visible','no', 2020, 01,01, '/', 'domain.com'); } else { delete_cookie('visible'); } $(".help").slideToggle(); $("#wrapper").animate({ opacity: 1.0 },200).slideToggle(200, function() { $("#slid img").toggle(); }); }); Im trying to set the cookie for all pages that exist under domain.com with the path '/'. However using these functions and jQuery it doesn't appear to be working, any anyone give me an idea of where im going wrong?

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  • How to implement conditional render in JS?

    - by mare
    Below is the JS (jQuery) code of autocomplete's result function. You can see there's some lines where I print out <li>s containing some data properties (that come in as a result of automcomplete's AJAX call). How could I rewrite this so that <li> would be conditionally rendered based on whether the property contains any value being either int or string (not empty string or whitespace) or something else that can be represented as string? $(".clients-dropdown").result(function (event, data, formatted) { if (data) { // set the hidden input that we need for Client entity rematerialize $(".client-id").val(data.client_id); if (data.ClientName && data.Address1 && data.postalcode && data.postname) { $(".client-address").html( "<li>" + data.ClientName + "</li>" + "<li>" + data.Address1 + "</li>" + "<li>" + data.postalcode + " " + data.postname + "</li>" ); $(".client-details").html( "<li>" + data.PrettyId + "</li>" + "<li>" + data.VatNo + "</li>" + "<li>" + data.Phone + "</li>" + "<li>" + data.Mobile + "</li>" + "<li>" + data.Email1 + "</li>" + "<li>" + data.Contact + "</li>" ); } } Also, for the AJAX call, should my server side action return null when there's a null for a property in the database or empty string?

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  • How to use dirent.h correctly.

    - by Nick
    Hello, I am new to C++ and I am experimenting with the dirent.h header to manipulate directory entries. The following little app compiles but pukes after you supple a directory name. Can someone give me a hint? The int quit is there to provide a while loop. I removed the loop in an attempt to isolate my problem. thanks! #include <iostream> #include <dirent.h> using namespace std; int main() { char *dirname = 0; DIR *pd = 0; struct dirent *pdirent = 0; int quit = 1; cout<< "Enter a directory path to open (leave blank to quit):\n"; cin >> dirname; if(dirname == NULL) { quit = 0; } pd = opendir(dirname); if(pd == NULL) { cout << "ERROR: Please provide a valid directory path.\n"; } return 0; }

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