Search Results

Search found 21111 results on 845 pages for 'null pointer'.

Page 634/845 | < Previous Page | 630 631 632 633 634 635 636 637 638 639 640 641  | Next Page >

• SQLce create table "index field" explanation (SQL Management Studio) ?

  - by bretddog

  Hi, I'm new to databases, and now creating SQLCE database in Management Studio. There is a value in brackets; [UQ_Users_0000000000000028], which seems a bit random to me, so would just like to ask if someone could explain this field? Is it just simply required to be a unique field? Is there any reason why I would want to change it to something else than what SSMS scripts? cheers! CREATE TABLE [Users] ( [UserID] int NOT NULL ..... CREATE UNIQUE INDEX [UQ__Users__0000000000000028] ON [Users] ([UserID] ASC);

  Read the article

• Best practice for creating objects used in for/foreach loops

  - by StupidDeveloper

  Hi! What's the best practice for dealing with objects in for or foreach loops? Should we create one object outside the loops and recreate it all over again (using new... ) or create new one for every loop iteration? Example: foreach(var a in collection) { SomeClass sc = new SomeClass(); sc.id = a; sc.Insert(); } or SomeClass sc = null; foreach(var a in collection) { sc = new SomeClass(); sc.id = a; sc.Insert(); } Which is better?

  Read the article

• Trying to call JS Code that is passed back from AJAX call....

  - by Dutchie432

  Okay, so I have an javascript function that retrieves some HTML... function updateQuestions(i){ var url = 'getQuestions.php?sys=' + i; if (receiveReq.readyState == 4 || receiveReq.readyState == 0) { receiveReq.open("GET", url, true); receiveReq.onreadystatechange = handleQuestionsUpdate; receiveReq.send(null); } } function handleQuestionsUpdate() { if (receiveReq.readyState == 4) { var a=receiveReq.responseText; document.getElementById('questions').innerHTML=a; checkSpeakers(); //Error Occurs Here, even though checkSpeakers() is a function in the returned HTML chunk. } } This HTML is not just HTML, but it is more specifically a form and a chunk of javascript. The javascript is hard-coded into the HTML and not referenced by <script src=".."> Is it normal that this retrieved JS code isn't recognized upon call-time? If so, what is my alternative if I need the JS to change every time the div is update? Now

  Read the article

• How to set focus to a control inside frame

  - by Geetha

  Hi All, i am using two frames in a page. Mainframe have a page with text box to get input and gives the result url. Needs: I want to show this page in the topframe. I want to set focus to the text box control in the mainframe always. using the following code but giving null error. parent.frames['mainFrame'].document.getElementById('form1:txtbox').focus(); <frameset rows="550,0" cols="1008" frameborder="NO" border="0" framespacing="0"> <frame src="" id="topFrame" target="topFrame" runat="server" scrolling="no"></frame> <frame src="Search.aspx" runat="server" id="mainFrame"></frame> </frameset>

  Read the article

• Trying to use tcl threads on windows 7 results in access violation.

  - by Juan

  I'm trying to get this simple program to work on windows, but it crashes: unsigned (__stdcall testfoo)(ClientData x) { return 0; } int main() { Tcl_ThreadId testid = 0; Tcl_CreateThread(&testid, testfoo, (ClientData) NULL, TCL_THREAD_STACK_DEFAULT, TCL_THREAD_NOFLAGS); } I am using a makefile generated by cmake and linking against a version of Tcl 8.5.7 I compiled myself using Visual C++ 2008 express. It was compiled using msvcrt,static,threads and the name of the resulting library is tcl85tsx.lib. The error is: Unhandled exception at 0x77448c39 in main.exe: 0xC0000005: Access violation writing location 0x00000014. The Tcl library works fine, and I can even run a threading script example by loading the Thread extension into it. My assumption is that there is something horribly wrong with a memory violation, but I have no idea what. Any help appreciated.

  Read the article

• Is it bad practice to initialize a variable to a dummy value?

  - by froadie

  This question is a result of the answers to this question that I just asked. It was claimed that this code is "ugly" because it initializes a variable to a value that will never be read: String tempName = null; try{ tempName = buildFileName(); } catch(Exception e){ ... System.exit(1); } FILE_NAME = tempName; Is this indeed bad practice? Should one avoid initializing variables to dummy values that will never actually be used? (EDIT - And what about initializing a String variable to "" before a loop that will concatenate values to the String...? Or is this in a separate category? e.g. String whatever = ""; for(String str : someCollection){ whatever += str; } )

  Read the article

• Plagued by multithreaded bugs

  - by koncurrency

  On my new team that I manage, the majority of our code is platform, TCP socket, and http networking code. All C++. Most of it originated from other developers that have left the team. The current developers on the team are very smart, but mostly junior in terms of experience. Our biggest problem: multi-threaded concurrency bugs. Most of our class libraries are written to be asynchronous by use of some thread pool classes. Methods on the class libraries often enqueue long running taks onto the thread pool from one thread and then the callback methods of that class get invoked on a different thread. As a result, we have a lot of edge case bugs involving incorrect threading assumptions. This results in subtle bugs that go beyond just having critical sections and locks to guard against concurrency issues. What makes these problems even harder is that the attempts to fix are often incorrect. Some mistakes I've observed the team attempting (or within the legacy code itself) includes something like the following: Common mistake #1 - Fixing concurrency issue by just put a lock around the shared data, but forgetting about what happens when methods don't get called in an expected order. Here's a very simple example: void Foo::OnHttpRequestComplete(statuscode status) { m_pBar->DoSomethingImportant(status); } void Foo::Shutdown() { m_pBar->Cleanup(); delete m_pBar; m_pBar=nullptr; } So now we have a bug in which Shutdown could get called while OnHttpNetworkRequestComplete is occuring on. A tester finds the bug, captures the crash dump, and assigns the bug to a developer. He in turn fixes the bug like this. void Foo::OnHttpRequestComplete(statuscode status) { AutoLock lock(m_cs); m_pBar->DoSomethingImportant(status); } void Foo::Shutdown() { AutoLock lock(m_cs); m_pBar->Cleanup(); delete m_pBar; m_pBar=nullptr; } The above fix looks good until you realize there's an even more subtle edge case. What happens if Shutdown gets called before OnHttpRequestComplete gets called back? The real world examples my team has are even more complex, and the edge cases are even harder to spot during the code review process. Common Mistake #2 - fixing deadlock issues by blindly exiting the lock, wait for the other thread to finish, then re-enter the lock - but without handling the case that the object just got updated by the other thread! Common Mistake #3 - Even though the objects are reference counted, the shutdown sequence "releases" it's pointer. But forgets to wait for the thread that is still running to release it's instance. As such, components are shutdown cleanly, then spurious or late callbacks are invoked on an object in an state not expecting any more calls. There are other edge cases, but the bottom line is this: Multithreaded programming is just plain hard, even for smart people. As I catch these mistakes, I spend time discussing the errors with each developer on developing a more appropriate fix. But I suspect they are often confused on how to solve each issue because of the enormous amount of legacy code that the "right" fix will involve touching. We're going to be shipping soon, and I'm sure the patches we're applying will hold for the upcoming release. Afterwards, we're going to have some time to improve the code base and refactor where needed. We won't have time to just re-write everything. And the majority of the code isn't all that bad. But I'm looking to refactor code such that threading issues can be avoided altogether. One approach I am considering is this. For each significant platform feature, have a dedicated single thread where all events and network callbacks get marshalled onto. Similar to COM apartment threading in Windows with use of a message loop. Long blocking operations could still get dispatched to a work pool thread, but the completion callback is invoked on on the component's thread. Components could possibly even share the same thread. Then all the class libraries running inside the thread can be written under the assumption of a single threaded world. Before I go down that path, I am also very interested if there are other standard techniques or design patterns for dealing with multithreaded issues. And I have to emphasize - something beyond a book that describes the basics of mutexes and semaphores. What do you think? I am also interested in any other approaches to take towards a refactoring process. Including any of the following: Literature or papers on design patterns around threads. Something beyond an introduction to mutexes and semaphores. We don't need massive parallelism either, just ways to design an object model so as to handle asynchronous events from other threads correctly. Ways to diagram the threading of various components, so that it will be easy to study and evolve solutions for. (That is, a UML equivalent for discussing threads across objects and classes) Educating your development team on the issues with multithreaded code. What would you do?

  Read the article

• Getting MATLAB variable (string) from C

  - by Hamming

  Hi! I'm writing a small C application that launchs a Matlab script (.m file). I need to exchange some variables and I don't know how to get an array of chars that exists in Matlab. I'm doing something like this: enter code here result = engGetVariable(ep,"X"); if (!result) { printf ("Error..."); exit -1; } int n = mxGetN(result); char *varx = NULL; memcpy(varx, mxGetData(result),n*sizeof(char)); It doesn't work. Does someone know how to get a Matlab string in C? I've read Matlab documentation about engGetVariable() and the provided example but any of this things clarify me.

  Read the article

• How to assign one object to another in Linq c# without making new

  - by LLL

  I m facing issue in assiging one object to another in linq sql. In this example Func<result, result> make = q => new result { Id = q.Id, lName = q.lName, GroupId = q.GroupId, Age = (from tags in q.age where tags.Del == null && tags.lId == q.Id select age).ToEntitySet(), }; p = (from q in dc.results where q.Id == Id.Value select make(q)).First(); i am making new and assigning the object, but i dont want to do this, it will cause propblem in insertion. so i want to assign without making new, how is it possible?

  Read the article

• asp.net could a half submitted web page be processed?

  - by c00ke

  Having a weird bug in production and just wondering if it's possible for a half submitted web page to processed by the server? The page has no view state just using plain old html controls and accessing data displayed in repeater on the back end via Request.Form[name] etc. Is it possible for a request to be truncated perhaps due to lost internet connection and the page still processed by the server. Therefore if field not part of the request Request.Form[name] could result in null? I know can use fiddler to modify request but unfortunately we are not allowed to change group policy and change the proxy! Many Thanks

  Read the article

• Need help... how to add md5 to password field in php?

  - by jones

  Hi mates, i looking some help and nice attention here.. i bought some php script many years ago and now no suport anymore... i just want to add md5 to password field.. here my form: <?php $SQL = "SELECT * from USERS WHERE USERNAME = '$_SESSION[username]'"; $result = @mysql_query( $SQL ); $row = @mysql_fetch_array( $result ); include 'menu.php'; ?> <FORM METHOD="post" ACTION="?page=query_client"> <INPUT TYPE="hidden" NAME="controller" VALUE="USERS~update~account_details&up=1~<?php echo $row[ID]; ?>"> <TABLE CLASS="basictable"> <TR> <TD CLASS="tdmenu" WIDTH="40%">Username</TD> <TD CLASS="tdmenu" WIDTH="60%"> <b><?php echo $row[USERNAME]; ?></b> </TD> </TR> <TR> <TD CLASS="tdmenu" WIDTH="40%">Password *</TD> <TD CLASS="tdmenu" WIDTH="60%"> <INPUT TYPE="PASSWORD" NAME="PASSWORD" SIZE="40" VALUE="<?php echo $row[PASSWORD]; ?>"> </TD> </TR> <TR> <TD CLASS="tdmenu" WIDTH="40%">Email Address *</TD> <TD CLASS="tdmenu" WIDTH="60%"> <INPUT TYPE="text" NAME="EMAIL" SIZE="40" VALUE="<?php echo $row[EMAIL]; ?>"> </TD> </TR> <TR> <TD CLASS="tdmenu" WIDTH="40%">Full Name *</TD> <TD CLASS="tdmenu" WIDTH="60%"> <INPUT TYPE="text" NAME="FULLNAME" SIZE="40" VALUE="<?php echo $row[FULLNAME]; ?>"> </TD> <TR> <TD CLASS="tdmenu" WIDTH="40%">Address *</TD> <TD CLASS="tdmenu" WIDTH="60%"> <INPUT TYPE="text" NAME="ADDRESS1" SIZE="40" VALUE="<?php echo $row[ADDRESS1]; ?>"> </TD> </TR> <BR> <TABLE CLASS="basictable"> <TR> <TD CLASS="tdhead2" > <DIV ALIGN="CENTER"><B> <INPUT TYPE="submit" NAME="Submit" VALUE="Submit"> </B></DIV> </TD> </TR> </TABLE> </FORM> and the it self as query_client.php inside look like: <?PHP @session_start(); $controller = $_POST['controller']; $pieces = explode("~", $controller); $table = $pieces[0]; $qt = $pieces[1]; $return = $pieces[2]; $id = $pieces[3]; $hack = $pieces[4]; if ($qt == insert) $qt = 'INSERT INTO'; if ($qt == update) { $qt = 'UPDATE'; $end = "WHERE ID = '$id'"; } $pre = array_keys( $_POST ); mysql_query ("CREATE TABLE IF NOT EXISTS `$table` (`ID` INT NOT NULL AUTO_INCREMENT , PRIMARY KEY ( `id` ) )"); $count = count($pre); $count = $count - 2; $sql = "$qt $table SET"; for ($i=0; $i < $count; $i++) { $x=$i+1; $y = $_POST[$pre[$x]]; $d = $y; mysql_query ("ALTER TABLE `$table` ADD `$pre[$x]` TEXT NOT NULL"); $sql .= " `$pre[$x]` = '$d',"; } $sql .= " ID = '$id' $end"; $query = mysql_query($sql) or die("$sql_error" . mysql_error()); if (empty($hack)) { } else { $pieces = explode("/", $hack); $h0 = $pieces[0]; $h1 = $pieces[1]; $h2 = $pieces[2]; $h3 = $pieces[3]; $h4 = $pieces[4]; $h5 = $pieces[5]; mysql_query ("ALTER TABLE `$table` $h0 $h1 $h2 $h3 $h4 $h5"); $query = mysql_query($sql) or die("$sql_error" . mysql_error()); } if (isset($_GET[inc])) include "$_GET[inc].php"; ?> so please help me how to add md5 in PASSWORD field? thanks in advance..

  Read the article

• Regular Expression Program

  - by david robers

  Hi I have the following text: SMWABCCA ABCCAEZZRHM NABCCAYJG XABCCA ABCCADK ABCCASKIYRH ABCCAKY PQABCCAK ABCCAKQ This method takes a regex in out by the user and SHOULD print out the Strings it applies to but seems to print out something completely different: private void matchIt(String regex) { Pattern p = Pattern.compile(regex); Matcher m = null; boolean found = false; for(int i = 0; i < data.length; i++){ m = p.matcher(data[i]); if(m.find()){ out.println(data[i]); found = true; } } if(!found){ out.println("Pattern Not Found"); } } When inputting "[C]" It outputs: SMWABCCA ABCCAEZZRHM NABCCAYJG XABCCA ABCCADK ABCCASKIYRH ABCCAKY PQABCCAK ABCCAKQ Any ideas why? I think I'm using m.find() improperly...

  Read the article

• sound not playing when i press the button and how to fix overlapping sounds

  - by alfredjunco

  the code is giving me an error"Unused variable'path'" and when i press a button there is no sound playing how do i fix this the aSound is in the h file - (void)playOnce:(NSString *)aSound; - (IBAction) beatButton50 { [self playOnce:@"racecars"]; } - (void)playOnce:(NSString *)aSound { NSString *path = [[NSBundle mainBundle] pathForResource:aSound ofType:@"caf"]; if([theAudio isPlaying]) { [theAudio stop]; } } - (void)playLooped:(NSString *)aSound { NSString *path = [[NSBundle mainBundle] pathForResource:aSound ofType:@"caf"]; if (!theAudio) { theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL: [NSURL fileURLWithPath: path] error: NULL]; } [theAudio setDelegate: self]; // loop indefinitely [theAudio setNumberOfLoops: -1]; [theAudio setVolume: 1.0]; [theAudio play]; } - (void)stopAudio { [theAudio stop]; [theAudio setCurrentTime:0]; }

  Read the article

• Many Buttons on a Page, Need to send back Unique Post Data with each

  - by CoffeeAddict

  I'm listing out a bunch of cars with a button next to them that when clicked will need to perform a GET but also sends over that item's model.Name: @using (Html.BeginForm("GetCarUrl", "Car", FormMethod.Get, new { model = Model })) { if(Model.Cars != null && Model.Cars.Count > 0) { foreach (CarContent car in Model.Cars) { <p>@car.Name</p> } <input type="button" value="Get Car Url" class="submit" /> } So the page renders a bunch of hyperlinks and buttons: [hyperlink1] [submit] [hyperlink2] [submit] [hyperlink3] [submit] [hyperlink4] [submit] [hyperlink5] [submit] ... When a user clicks on any of the submits, I need to pass back its corresponding @car.CarType for that specific hyperlink Not sure how to go about this. My action method expects a @car.CarType for that specific car hyperlink to be sent to it

  Read the article

• Using Linq to filter parents by their children

  - by Nick L

  Having some problems with my Silverlight app (with RIA services) filtering my results. The idea is on the client I set up the EntityQuery and its filters and call load. However this isn't working for me. Heres my code. public void FireQuery(string filterValue) { EntityQuery<Parent> query = m_ParentDomainContext.GetParentQuery(); query = query.Where(p => p.Children.Any(c => c.Name.Contains(filterValue))); m_ParentDomainContext.Load(query, Query_Completed, null); } Compiles just fine, however, runtime I get "Query operator 'Any' is not supported." Exception. Does anyone know of a good way to filter like this? Again, I'm looking for a way to set this up on the client.

  Read the article

• How to handle Foreign Keys with Entity Framework

  - by Jack Marchetti

  I have two entities. Groups. Pools. A Group can create many pools. So I setup my Pool table to have a GroupID foreign key. My code: using (entity _db = new entity()) { Pool p = new Pool(); p.Name = "test"; p.Group.ID = "5"; _db.AddToPool(p); } This doesn't work. I get a null reference exception on p.Group. How do I go about creating a new "Pool" and associating a GroupID?

  Read the article

• Objective-C retain clarification

  - by Maverick

  I'm looking at this code: NSMutableArray *controllers = [[NSMutableArray alloc] init]; for (unsigned i = 0; i < kNumberOfPages; i++) { [controllers addObject:[NSNull null]]; } self.viewControllers = controllers; [controllers release]; Later on... - (void)dealloc { [viewControllers release]; ... } I see that self.viewControllers and controllers now point to the same allocated memory (of type NSMutableArray *), but when I call [controllers release] isn't self.viewControllers released as well, or is setting self.viewControllers = controllers automatically retains that memory?

  Read the article

• Check constraint on table lookup

  - by bzamfir

  Hi, I have a table, department , with several bit fields to indicate department types One is Warehouse (when true, indicate the department is warehouse) And I have another table, ManagersForWarehouses with following structure: ID autoinc WarehouseID int (foreign key reference DepartmentID from departments) ManagerID int (foreign key reference EmployeeID from employees) StartDate EndDate To set new manager for warehouse, I insert in this table with EndDate null, and I have a trigger that sets EndDate for previous record for that warehouse = StartDate for new manager, so a single manager appears for a warehouse at a certain time. I want to add two check constraints as follows, but not sure how to do this do not allow to insert into ManagersForWarehouses if WarehouseID is not marked as warehouse Do not allow to uncheck Warehouse if there are records in ManagersForWarehouses Thanks

  Read the article

• Want to avoid the particular rows from select join query... See description

  - by OM The Eternity

  I have a Select Left Join Query whis displays me the rows for the latest changedone(its a time) column name ("field" should not be equal) column name ("trackid" should not be equal), and column name "Operation should be "UPDATE" ", below is the query I am talking about... SELECT j1. * FROM jos_audittrail j1 LEFT OUTER JOIN jos_audittrail j2 ON ( j1.trackid != j2.trackid AND j1.field != j2.field AND j1.changedone < j2.changedone ) WHERE j1.operation = 'UPDATE' AND j2.id IS NULL Now here I don't want a row to be displayed with a two particular column's value i.e. "field's value" the value is "LastvisitDate" and "hits" Now if if append the condition in the above query that " AND j1.field != 'lastvistDate' AND j1.field != 'hits' " theni do not get any result... The table structure is jos_audittrail: id trackid operation oldvalue newvalue table_name live changedone(its a time) I hope i have given the details properly If u still find something missing I will try to provide it more better way... Pls help me to avoid those two rows with those to mentioned value of "field"

  Read the article

• simple query Delete records in a table based on count logic

  - by user1905941

  a table with a pk and status column which is having values as 'Y','N','NULL' Query: get the count of records with status column as 'Y', if this count exceeds 1% of total count of records then dont delete , else delete the records in the table. i tried like this Declare v_count Number; v_count1 Number; BEGIN v_count := select count(*) from temp; v_count1 := select count(*) from temp where status = 'Y' ; v_count := v_count + ((0.1) * (v_count)) if (v_count1 > v_count) { insert into temp1 values(pk,status) } else { Delete from temp ; } END;

  Read the article

• What is wrong with this simple update query?

  - by Kyle Noland

  I get no error message, but the row is not updated. The rows integer is set 1 following the query, indicating that 1 row was affected. String query = "UPDATE contacts SET contact_name = '" + ContactName.Text.Trim() + "', " + "contact_phone = '" + Phone.Text.Trim() + "', " + "contact_fax = '" + Fax.Text.Trim() + "', " + "contact_direct = '" + Direct.Text.Trim() + "', " + "company_id = '" + Company.SelectedValue + "', " + "contact_address1 = '" + Address1.Text.Trim() + "', " + "contact_address2 = '" + Address2.Text.Trim() + "', " + "contact_city = '" + City.Text.Trim() + "', " + "contact_state = '" + State.SelectedValue + "', " + "contact_zip = '" + Zip.Text.Trim() + "' " + "WHERE contact_id = '" + contact_id + "'"; String cs = Lib.GetConnectionString(null); SqlConnection conn = new SqlConnection(cs); SqlCommand cmd = conn.CreateCommand(); cmd.CommandText = query; cmd.Connection.Open(); int rows = cmd.ExecuteNonQuery();

  Read the article

• Set a tab page on lload event of a form

  - by tanu

  i have a form with many tabs on it. I want to set a specific tab page to show on load of the form everytime i load the form I used TabPageControl1.SelectedTab=MyTabPage; but the value of selectedtab is null. It is throwing an exception that reference not set to an object. private void PreferencesForm_Load(object sender, EventArgs e) { this.cbxCustomDataType.DrawMode = DrawMode.OwnerDrawFixed; this.cbxCustomDataType.DrawItem += new DrawItemEventHandler(cbxCustomDataType_DrawItem); this.cbxColumnDataType.DrawMode = DrawMode.OwnerDrawFixed; this.cbxColumnDataType.DrawItem += new DrawItemEventHandler(cbxColumnDataType_DrawItem); GetProjectDetails(); this.preferencesTabControl.SelectedTab= tpCompareUpdate; }

  Read the article

• ActiveRecord date format

  - by Mongus Pong

  I've run into a spot of bother with date formats in our Rails application. I have a date field in our view which I want to be formatted as dd/mm/yy. This is how the user will expect to enter their dates, and the datepicker control uses this format. However, Active Record seems to be expecting mm/dd/yy. If I enter 01/03/2010, this gets put in as 03 January 2010. If I enter 25/03/2010, this gets put in a null. How do I get ActiveRecord to expect Her Majesties date format?

  Read the article

• User class - 'load' data

  - by John

  <?php class User { private $id; private $username; public function __construct($id = null) { $this->id = $id; if (!is_null($this->id)) { $this->load(); } } public function load() { } } ?> In the 'load' method I am going to load all the information from the current user (id) But I wonder how is the best way to load all info. I could grab all data and then just assign all private variables, but I assume there must be another "cheaper" way to get all the data so I can use as such $this-variable; And not have to ASSIGN every single data row, I select in the load method. How?

  Read the article

• linq2sql left join with "multiselect"

  - by just_azho

  Hi, folks I'm trying to achieve following by linq2sql, but not successful. I've Member and Reference tables. DB is design in such a manner that Member can have multiple (=0) References. What I want as a result of query is, list (rows) of members, where all references of the member are "collected" in one column. What I had achieved is following query, but for this one there exist a row for each Reference. var refs = (from m in db.Members join r in db.References on m.PID equals r.PID into g from o in g.DefaultIfEmpty() select new { member = m, name = (o == null ? "" : o.NameSurname) }); I feel I need to insert SelectMany somewher :) Could you please give hints on achieving the goal?

  Read the article

< Previous Page | 630 631 632 633 634 635 636 637 638 639 640 641  | Next Page >