Search Results

Search found 29194 results on 1168 pages for 'non null'.

Page 317/1168 | < Previous Page | 313 314 315 316 317 318 319 320 321 322 323 324  | Next Page >

  • Updating MS Access Database from Datagridview

    - by Peter Roche
    I am trying to update an ms access database from a datagridview. The datagridview is populated on a button click and the database is updated when any cell is modified. The code example I have been using populates on form load and uses the cellendedit event. private OleDbConnection connection = null; private OleDbDataAdapter dataadapter = null; private DataSet ds = null; private void Form2_Load(object sender, EventArgs e) { string connetionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source='C:\\Users\\Peter\\Documents\\Visual Studio 2010\\Projects\\StockIT\\StockIT\\bin\\Debug\\StockManagement.accdb';Persist Security Info=True;Jet OLEDB:Database Password="; string sql = "SELECT * FROM StockCount"; connection = new OleDbConnection(connetionString); dataadapter = new OleDbDataAdapter(sql, connection); ds = new DataSet(); connection.Open(); dataadapter.Fill(ds, "Stock"); connection.Close(); dataGridView1.DataSource = ds; dataGridView1.DataMember = "Stock"; } private void addUpadateButton_Click(object sender, EventArgs e) { } private void dataGridView1_CellEndEdit(object sender, DataGridViewCellEventArgs e) { try { dataadapter.Update(ds,"Stock"); } catch (Exception exceptionObj) { MessageBox.Show(exceptionObj.Message.ToString()); } } The error I receive is Update requires a valid UpdateCommand when passed DataRow collection with modified rows. I'm not sure where this command needs to go and how to reference the cell to update the value in the database.

    Read the article

  • Java InputReader. Detect if file being read is binary?

    - by Trizicus
    I had posted a question in regards to this code. I found that JTextArea does not support the binary type data that is loaded. So my new question is how can I go about detecting the 'bad' file and canceling the file I/O and telling the user that they need to select a new file? class Open extends SwingWorker<Void, String> { File file; JTextArea jta; Open(File file, JTextArea jta) { this.file = file; this.jta = jta; } @Override protected Void doInBackground() throws Exception { BufferedReader br = null; try { br = new BufferedReader(new FileReader(file)); String line = br.readLine(); while(line != null) { publish(line); line = br.readLine(); } } finally { try { br.close(); } catch (IOException e) { } } return null; } @Override protected void process(List<String> chunks) { for(String s : chunks) jta.append(s + "\n"); } }

    Read the article

  • Qt/C++, Problems with large QImage

    - by David Günzel
    I'm pretty new to C++/Qt and I'm trying to create an application with Visual Studio C++ and Qt (4.8.3). The application displays images using a QGraphicsView, I need to change the images at pixel level. The basic code is (simplified): QImage* img = new QImage(img_width,img_height,QImage::Format_RGB32); while(do_some_stuff) { img->setPixel(x,y,color); } QGraphicsPixmapItem* pm = new QGraphicsPixmapItem(QPixmap::fromImage(*img)); QGraphicsScene* sc = new QGraphicsScene; sc->setSceneRect(0,0,img->width(),img->height()); sc->addItem(pm); ui.graphicsView->setScene(sc); This works well for images up to around 12000x6000 pixel. The weird thing happens beyond this size. When I set img_width=16000 and img_height=8000, for example, the line img = new QImage(...) returns a null image. The image data should be around 512,000,000 bytes, so it shouldn't be too large, even on a 32 bit system. Also, my machine (Win 7 64bit, 8 GB RAM) should be capable of holding the data. I've also tried this version: uchar* imgbuf = (uchar*) malloc(img_width*img_height*4); QImage* img = new QImage(imgbuf,img_width,img_height,QImage::Format_RGB32); At first, this works. The img pointer is valid and calling img-width() for example returns the correct image width (instead of 0, in case the image pointer is null). But as soon as I call img-setPixel(), the pointer becomes null and img-width() returns 0. So what am I doing wrong? Or is there a better way of modifying large images on pixel level? Regards, David

    Read the article

  • SQL Server Table Partitioning, what is happening behind the scenes?

    - by user404463
    I'm working with table partitioning on extremely large fact table in a warehouse. I have executed the script a few different ways. With and without non clustered indexes. With indexes it appears to dramatically expand the log file while without the non clustered indexes it appears to not expand the log file as much but takes more time to run due to the rebuilding of the indexes. What I am looking for is any links or information as to what is happening behind the scene specifically to the log file when you split a table partition.

    Read the article

  • Raising C# events with an extension method - is it bad?

    - by Kyralessa
    We're all familiar with the horror that is C# event declaration. To ensure thread-safety, the standard is to write something like this: public event EventHandler SomethingHappened; protected virtual void OnSomethingHappened(EventArgs e) { var handler = SomethingHappened; if (handler != null) handler(this, e); } Recently in some other question on this board (which I can't find now), someone pointed out that extension methods could be used nicely in this scenario. Here's one way to do it: static public class EventExtensions { static public void RaiseEvent(this EventHandler @event, object sender, EventArgs e) { var handler = @event; if (handler != null) handler(sender, e); } static public void RaiseEvent<T>(this EventHandler<T> @event, object sender, T e) where T : EventArgs { var handler = @event; if (handler != null) handler(sender, e); } } With these extension methods in place, all you need to declare and raise an event is something like this: public event EventHandler SomethingHappened; void SomeMethod() { this.SomethingHappened.RaiseEvent(this, EventArgs.Empty); } My question: Is this a good idea? Are we missing anything by not having the standard On method? (One thing I notice is that it doesn't work with events that have explicit add/remove code.)

    Read the article

  • Actionscript 3: How to remove all black pixels from BitmapData ?

    - by Adnan Doric
    Hello, Let say I have a BitmapData with different pixels representing an object, and some black pixels around it that I want to remove. I would like to obtain a new BitmapData, with width and height of the object represented by non-black pixels. For example, let say I have a BitmapData 400x400px, but the object represented by non-black pixels occupies the rect: x=100, y=100, width=200, height=200. I want to get new BitmapData representing that rect, all black pixels should be removed. Any idea on how to do this please ?

    Read the article

  • Is there a tool that can refactor this C code correctly?

    - by Alex
    Lets say I have the following code (the array* function are what we use for resizable arrays and they operate on pointers-to-arrays that are null initialized): typedef struct MyStruct { int i; } MyStruct; MyStruct* GetNewMyStruct(int i) { MyStruct* s = malloc(sizeof(MyStruct)); s->i = i; return s; } int SomeFunction(int number, MyStruct *elem) { MyStruct **structs = NULL; int i; for (i = 0; i < number; i++) arrayPush(&structs, GetNewMyStruct(i)); arrayPush(&structs, elem); return arraySize(&structs); } I decide that SomeFunction is too large and I want refactor it. Currently where I work we use VisualAssist X, which has some refactoring capabilities, but when I use it on this it does not work correctly. If I attempt to use it to refactor out the loop, this is what I get: void MyMethod( int number, MyStruct ** structs ) { int i; for (i = 0; i < number; i++) arrayPush(&structs, GetNewMyStruct(i)); } int SomeFunction(int number, MyStruct *elem) { MyStruct **structs = NULL; MyMethod(number, structs); arrrayPush(&structs, elem); return arraySize(&structs); } This is not correct. MyMethod should take a MyStruct ***, not a MyStruct **. This is because the code I'm refactoring takes the address of structs. The result is that the refactored version will always return 1 (since only one object has been pushed into my array) rather than number+1. Are there other tools out there that do this type of refactoring correctly?

    Read the article

  • Silverlight 5 App Crashing

    - by bbagfh
    I have a silverlight 5 app that makes some WCF requests. When the silverlight app is hosted locally on an IIS 7.5 server it works fine, but when I run it from a remote IIS6 box there are issues. The app loads fine and presents the login UI. After trying to log in, a couple WCF service calls are made (successfully), but the response causes silverlight to stop responding and the browser eventually asks to kill the non-responsive silverlight app. I am mostly confused because it works fine in IIS 7.5 Note that I am accessing the same WCF services hosted on a remote box in both instances, and both times I am getting successful responses. It is only in IIS6 that the app becomes non-responsive.

    Read the article

  • sorting names in a linked list

    - by sil3nt
    Hi there, I'm trying to sort names into alphabetical order inside a linked list but am getting a run time error. what have I done wrong here? #include <iostream> #include <string> using namespace std; struct node{ string name; node *next; }; node *A; void addnode(node *&listpointer,string newname){ node *temp; temp = new node; if (listpointer == NULL){ temp->name = newname; temp->next = listpointer; listpointer = temp; }else{ node *add; add = new node; while (true){ if(listpointer->name > newname){ add->name = newname; add->next = listpointer->next; break; } listpointer = listpointer->next; } } } int main(){ A = NULL; string name1 = "bob"; string name2 = "tod"; string name3 = "thomas"; string name4 = "kate"; string name5 = "alex"; string name6 = "jimmy"; addnode(A,name1); addnode(A,name2); addnode(A,name3); addnode(A,name4); addnode(A,name5); addnode(A,name6); while(true){ if(A == NULL){break;} cout<< "name is: " << A->name << endl; A = A->next; } return 0; }

    Read the article

  • How to deal with presence or not of xml namespaces using xslt.

    - by Mycol
    I have some XML/TEI documents, and i'm writing an XSLT 2.0 to extract their content. Almost all TEI documents has no namespace, but one has the default namespace (xmlns="http://www.tei-c.org/ns/1.0"). So all documents has the same aspect, with unqulified tags like <TEI> or <teiHeader>, but if I try to extract the content, all works with "non-namespaced-documents", but nothing (of course) is extracted from the namespaced-document. So i used the attribute xpath-default-namespace="http://www.tei-c.org/ns/1.0" and now (of course) the only document working is the namespaced one. I can't edit documents at all, so what I'm asking is if there's a way to change dynamically the xpath-default-namespace in order to make work xpaths like //teiHeader both with namespaced and non-namespaced documents

    Read the article

  • jQuery error when aborting an ajax call only in Internet Explorer

    - by Rob Crowell
    When mousing over an image in a jcarousel, my site displays a popup whose contents are loaded via ajax. I'm doing what I thought was fairly straightforward; keeping a handle to the xhrRequest object, and aborting the existing one before making a new request. It works great in all browsers except IE, where I receive an error "Object doesn't support this property or method" Here's the code that is triggering it: function showPopup { // ... code snipped ... // cancel the existing xhr request if (showPopup.xhrRequest != null) { showPopup.xhrRequest.abort(); showPopup.xhrRequest = null; } showPopup.xhrRequest = $.ajax({url: url, type: "GET", success:function(data) { $("#popup-content").html(data); } }); // ... code snipped ... } showPopup.xhrRequest = null; Works great in Firefox and Chrome. I traced the error down to this bit of code in jquery.js inside the ajax function (line 5233 in my copy of jQuery): // Override the abort handler, if we can (IE doesn't allow it, but that's OK) // Opera doesn't fire onreadystatechange at all on abort try { var oldAbort = xhr.abort; xhr.abort = function() { if (xhr ) { oldAbort.call( xhr ); } onreadystatechange( "abort" ); } catch(e) { } The specific error occurs on the oldAbort.call( xhr ) line. Any ideas?

    Read the article

  • What are the hibernate annotations used to persist a value typed Map with an enumerated type as a ke

    - by Jason Novak
    I am having trouble getting the right hibernate annotations to use on a value typed Map with an enumerated class as a key. Here is a simplified (and extremely contrived) example. public class Thing { public String id; public Letter startLetter; public Map<Letter,Double> letterCounts = new HashMap<Letter, Double>(); } public enum Letter { A, B, C, D } Here are my current annotations on Thing @Entity public class Thing { @Id public String id; @Enumerated(EnumType.STRING) public Letter startLetter; @CollectionOfElements @JoinTable(name = "Thing_letterFrequencies", joinColumns = @JoinColumn(name = "thingId")) @MapKey(columns = @Column(name = "letter", nullable = false)) @Column(name = "count") public Map<Letter,Double> letterCounts = new HashMap<Letter, Double>(); } Hibernate generates the following DDL to create the tables for my MySql database create table Thing (id varchar(255) not null, startLetter varchar(255), primary key (id)) type=InnoDB; create table Thing_letterFrequencies (thingId varchar(255) not null, count double precision, letter tinyblob not null, primary key (thingId, letter)) type=InnoDB; Notice that hibernate tries to define letter (my map key) as a tinyblob, however it defines startLetter as a varchar(255) even though both are of the enumerated type Letter. When I try to create the tables I see the following error BLOB/TEXT column 'letter' used in key specification without a key length I googled this error and it appears that MySql has issues when you try to make a tinyblob column part of a primary key, which is what hibernate needs to do with the Thing_letterFrequencies table. So I would rather have letter mapped to a varchar(255) the way startLetter is. Unfortunately, I've been fussing with the MapKey annotation for a while now and haven't been able to make this work. I've also tried @MapKeyManyToMany(targetEntity=Product.class) without success. Can anyone tell me what are the correct annotations for my letterCounts map so that hibernate will treat the letterCounts map key the same way it does startLetter?

    Read the article

  • Can I perform a search on mail server in Java?

    - by twofivesevenzero
    I am trying to perform a search of my gmail using Java. With JavaMail I can do a message by message search like so: Properties props = System.getProperties(); props.setProperty("mail.store.protocol", "imaps"); Session session = Session.getDefaultInstance(props, null); Store store = session.getStore("imaps"); store.connect("imap.gmail.com", "myUsername", "myPassword"); Folder inbox = store.getFolder("Inbox"); inbox.open(Folder.READ_ONLY); SearchTerm term = new SearchTerm() { @Override public boolean match(Message mess) { try { return mess.getContent().toString().toLowerCase().indexOf("boston") != -1; } catch (IOException ex) { Logger.getLogger(JavaMailTest.class.getName()).log(Level.SEVERE, null, ex); } catch (MessagingException ex) { Logger.getLogger(JavaMailTest.class.getName()).log(Level.SEVERE, null, ex); } return false; } }; Message[] searchResults = inbox.search(term); for(Message m:searchResults) System.out.println("MATCHED: " + m.getFrom()[0]); But this requires downloading each message. Of course I can cache all the results, but this becomes a storage concern with large gmail boxes and also would be very slow (I can only imagine how long it would take to search through gigabytes of text...). So my question is, is there a way of searching through mail on the server, a la gmail's search field? Maybe through Microsoft Exchange? Hours of Googling has turned up nothing.

    Read the article

  • How to copy an array of char pointers with a larger list of char pointers?

    - by Casey Link
    My function is being passed a struct containing, among other things, a NULL terminated array of pointers to words making up a command with arguments. I'm performing a glob match on the list of arguments, to expand them into a full list of files, then I want to replace the passed argument array with the new expanded one. The globbing is working fine, that is, g.gl_pathv is populated with the list of expected files. However, I am having trouble copying this array into the struct I was given. #include <glob.h> struct command { char **argv; // other fields... } void myFunction( struct command * cmd ) { char **p = cmd->argv; char* program = *p++; // save the program name (e.g 'ls', and increment to the first argument glob_t g; memset(&g, 0, sizeof(g)); int res = glob(*p, 0, NULL, &g); *p++ // increment while (*p) { glob(*p++, GLOB_APPEND, NULL, &g); // append the matches } // here i want to replace cmd->argv with the expanded g.gl_pathv memcpy(cmd->argv, g.gl_pathv, g.gl_pathc ); // this doesn't work globfree(&g); }

    Read the article

  • Turning a JSON list into a POJO

    - by Josh L
    I'm having trouble getting this bit of JSON into a POJO. I'm using Jackson configured like this: protected ThreadLocal<ObjectMapper> jparser = new ThreadLocal<ObjectMapper>(); public void receive(Object object) { try { if (object instanceof String && ((String)object).length() != 0) { ObjectDefinition t = null ; if (parserChoice==0) { if (jparser.get()==null) { jparser.set(new ObjectMapper()); } t = jparser.get().readValue((String)object, ObjectDefinition.class); } Object key = t.getKey(); if (key == null) return; transaction.put(key,t); } } catch (Exception e) { e.printStackTrace(); } } Here's the JSON that needs to be turned into a POJO: { "id":"exampleID1", "entities":{ "tags":[ { "text":"textexample1", "indices":[ 2, 14 ] }, { "text":"textexample2", "indices":[ 31, 36 ] }, { "text":"textexample3", "indices":[ 37, 43 ] } ] } And lastly, here's what I currently have for the java class: protected Entities entities; @JsonIgnoreProperties(ignoreUnknown = true) protected class Entities { public Entities() {} protected Tags tags; @JsonIgnoreProperties(ignoreUnknown = true) protected class Tags { public Tags() {} protected String text; public String getText() { return text; } public void setText(String text) { this.text = text; } }; public Tags getTags() { return tags; } public void setTags(Tags tags) { this.tags = tags; } }; //Getters & Setters ... I've been able to translate the more simple objects into a POJO, but the list has me stumped. Any help is appreciated. Thanks!

    Read the article

  • Uploading XML with NSInputStream Iphone....

    - by Aks
    Hi, I have to upload XML string to server & the Web service expect it in body stream part of the http request. So i am allocating the NSInputstream instance with xml data & then setting it the part of the http string but it uploading the stream body NULL & in my code if check the Stream status, it gives error & size null, Could you let me know how to get it done , also pasting the code. Code: NSInputStream* stream = [[[NSInputStream alloc]initWithData:streamData]retain]; request=[NSMutableURLRequest requestWithURL:[NSURL URLWithString:nss_url]]; NSString *msgLength = [NSString stringWithFormat:@"%d", [message length]]; [request addValue: @"text/xml; charset=utf-8" forHTTPHeaderField:@"Content-Type"]; [request addValue: @"http://www.XYZ.COM/ACL" forHTTPHeaderField:@"SOAPAction"]; [request addValue: msgLength forHTTPHeaderField:@"Content-Length"]; [request setHTTPBodyStream:[NSInputStream inputStreamWithData:streamData]]; [request setHTTPMethod:@"POST"]; NSLog(@"The input stream is %@ & error is %@",[stream streamStatus],[stream streamError]); Its gives: The input stream is (null) & error is Error Domain=NSUnknownErrorDomain Code=0 "Operation could not be completed. (NSUnknownErrorDomain error 0.)" Any inputs what I am missing ..........

    Read the article

  • how to recieve text sms to specific port..

    - by Umesh
    recieve text sms to specific port.. I have been looking for an answer to this question but but to no avail. This question has been popped a few times but nobody seems to have a clear answer. my code is as follows.. --MANIFEST FILE-- <receiver android:name=".SMSRecieve" android:enabled="true" <intent-filter <action android:name="android.intent.action.DATA_SMS_RECEIVED"/ <data android:scheme="sms" / <data android:host="localhost" / <data android:port="15005" / </intent-filter </receiver --SMS sending method-- String messageText = msgTxt.getText().toString(); short SMS_PORT = 15005; SmsManager smsManager = SmsManager.getDefault(); smsManager.sendDataMessage("5556", null, SMS_PORT, messageText.getBytes(), null, null); --Broadcast Reciever code-- static final String ACTION = "android.intent.action.DATA_SMS_RECEIVED"; //static final String ACTION = "android.provider.Telephony.SMS_RECEIVED";(tried this too, but failed) if (intent.getAction().equals(SMSNotifyExample.ACTION)) { ...do some work.. } I also tried to replace android:name to "android.provider.Telephony.SMS_RECEIVED" but the result is the same. my application does not recieve the SMS on the specified port. Once i remove the following line its works fine <data android:scheme="sms" / <data android:host="localhost" / <data android:port="15005" / could you suggest me what am i missing??

    Read the article

  • How to have a where clause on an insert or an update in Linq to Sql?

    - by Kelsey
    I am trying to convert the following stored proc to a LinqToSql call (this is a simplied version of the SQL): INSERT INTO [MyTable] ([Name], [Value]) SELECT @name, @value WHERE NOT EXISTS(SELECT [Value] FROM [MyTable] WHERE [Value] = @value) The DB does not have a constraint on the field that is getting checked for so in this specific case the check needs to be made manually. Also there are many items constantly being inserted as well so I need to make sure that when this specific insert happens there is no dupe of the value field. My first hunch is to do the following: using (TransactionScope scope = new TransactionScope()) { if (Context.MyTables.SingleOrDefault(t => t.Value == in.Value) != null) { MyLinqModels.MyTable t = new MyLinqModels.MyTable() { Name = in.Name, Value = in.Value }; // Do some stuff in the transaction scope.Complete(); } } This is the first time I have really run into this scenario so I want to make sure I am going about it the right way. Does this seem correct or can anyone suggest a better way of going about it without having two seperate calls? Edit: I am running into a similar issue with an update: UPDATE [AnotherTable] SET [Code] = @code WHERE [ID] = @id AND [Code] IS NULL How would I do the same check with Linqtosql? I assume I need to do a get and then set all the values and submit but what if someone updates [Code] to something other than null from the time I do the get to when the update executes? Same problem as the insert...

    Read the article

  • is it possible to display video information from an rtsp stream in an android app UI

    - by Joseph Cheung
    I have managed to get a working video player that can stream rtsp links, however im not sure how to display the videos current time position in the UI, i have used the getDuration and getCurrentPosition calls, stored this information in a string and tried to display it in the UI but it doesnt seem to work in main.xml: TextView android:id="@+id/player" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margin="1px" android:text="@string/cpos" / in strings.xml: string name="cpos""" /string in Player.java private void playVideo(String url) { try { media.setEnabled(false); if (player == null) { player = new MediaPlayer(); player.setScreenOnWhilePlaying(true); } else { player.stop(); player.reset(); } player.setDataSource(url); player.getCurrentPosition(); player.setDisplay(holder); player.setAudioStreamType(AudioManager.STREAM_MUSIC); player.setOnPreparedListener(this); player.prepareAsync(); player.setOnBufferingUpdateListener(this); player.setOnCompletionListener(this); } catch (Throwable t) { Log.e(TAG, "Exception in media prep", t); goBlooey(t); try { try { player.prepare(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } Log.v(TAG, "Duration: === " + player.getDuration()); } catch (IllegalStateException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } private Runnable onEverySecond = new Runnable() { public void run() { if (lastActionTime 0 && SystemClock.elapsedRealtime() - lastActionTime 3000) { clearPanels(false); } if (player != null) { timeline.setProgress(player.getCurrentPosition()); //stores getCurrentPosition as a string cpos = String.valueOf(player.getCurrentPosition()); System.out.print(cpos); } if (player != null) { timeline.setProgress(player.getDuration()); //stores getDuration as a string cdur = String.valueOf(player.getDuration()); System.out.print(cdur); } if (!isPaused) { surface.postDelayed(onEverySecond, 1000); } } };

    Read the article

  • How to wrtie a XML License Line(ended with a forward slash '/') in C#?

    - by Nano HE
    I want to write a XML file as below: <?xml version="1.0" encoding="UTF-8"?> <books xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <License licenseId="" licensePath="" /> Some piece of my code attached here // Create a new file in D:\\ and set the encoding to UTF-8 XmlTextWriter textWriter = new XmlTextWriter("D:\\books.xml", System.Text.Encoding.UTF8); // Format automatically textWriter.Formatting = Formatting.Indented; // Opens the document textWriter.WriteStartDocument(); // Write the namespace declaration. textWriter.WriteStartElement("books", null); // Write the genre attribute. textWriter.WriteAttributeString("xmlns", "xsd", null, "http://www.w3.org/2001/XMLSchema"); textWriter.WriteAttributeString("xmlns", "xsi", null, "http://www.w3.org/2001/XMLSchema-instance"); And now I need to write the License Line below in C# <License licenseId="" licensePath="" /> But I don't know how to move on for I found the Line ended with the forward slash / .Thank you.

    Read the article

  • Using Constraints on Hierarchical Data in a Self-Referential Table

    - by pbarney
    Suppose you have the following table, intended to represent hierarchical data: +--------+-------------+ | Field | Type | +--------+-------------+ | id | int(10) | | parent | int(10) | | name | varchar(45) | +--------+-------------+ The table is self-referential in that the parent_id refers to id. So you might have the following data: +----+--------+---------------+ | id | parent | name | +----+--------+---------------+ | 1 | 0 | fruit | | 2 | 0 | vegetable | | 3 | 1 | apple | | 4 | 1 | orange | | 5 | 3 | red delicious | | 6 | 3 | granny smith | | 7 | 3 | gala | +----+--------+---------------+ Using MySQL, I am trying to impose a (self-referential) foreign key constraint upon the data to update on cascades and prevent deletion of fruit if they have "children." So I used the following: CREATE TABLE `idtlp_main`.`fruit` ( `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT, `parent` INT(10) UNSIGNED, `name` VARCHAR(45) NOT NULL, PRIMARY KEY (`id`), CONSTRAINT `fk_parent` FOREIGN KEY (`parent`) REFERENCES `fruit` (`id`) ON UPDATE CASCADE ON DELETE RESTRICT ) ENGINE = InnoDB; From what I understand, this should fit my requirements. (And parent must default to null to allow insertions, correct?) The problem is, if I change the id of a record, it will not cascade: Cannot delete or update a parent row: a foreign key constraint fails (`iddoc_main`.`fruit`, CONSTRAINT `fk_parent` FOREIGN KEY (`parent`) REFERENCES `fruit` (`id`) ON UPDATE CASCADE) What am I missing? Feel free to correct me if my terminology is screwed up... I'm new to constraints.

    Read the article

  • GAE Datastore: persisting referenced objects

    - by David
    Two "I'm sorries" to begin with: 1) I've looked for a solution (here, and elsewhere), and couldn't find the answer. 2) English is not my mother tongue, so I may have some typos and the sort - please ignore them. To the point: I am trying to persist Java objects to the GAE datastore. I am not sure as to how to persist object having ("non-trivial") referenced object. That is, assume I have the following. public class Father { String name; int age; Vector<Child> offsprings; //this is what I call "non-trivial" reference //ctor, getters, setters... } public class Child { String name; int age; Father father; //this is what I call "non-trivial" reference //ctor, getters, setters... } The name field is unique in each type domain, and is considered a Primary-Key. In order to persist the "trivial" (String, int) fields, all I need is to add the correct annotation. So far so good. However, I don't understand how should I persist the home-brewed (Child, Father) types referenced. Should I: Convert each such reference to hold the Primary-Key (a name String, in this example) instead of the "actual" object. So, Vector<Child> offsprings; becomes Vector<String> offspringsNames; ? If that is the case, how do I handle the object at run-time? Do I just query for the Primary-Key from Class.getName, to retrieve the refrenced objects? Convert each such reference to hold the actual Key provided to me by the Datastore upon the proper put() operation? So, Vector<Child> offsprings; becomes Vector<Key> offspringsHashKeys; ? I would very much appreciate all kinds of comments. I have read ALL the offical relevant GAE docs/example. Throughout, they always persist "trivial" references, natively supported by the Datastore (e.g. in the Guestbook example, only Strings, and Longs). Many thanks, David

    Read the article

  • I find a problem with sending receiving parameter

    - by kawtousse
    how to get the xml translation to html dropdownlist with ajax. I send the parameter with GET method but the JSP FILE THAT GENERATES THE XML DONT RECEIVE IT. var url="responsexml.jsp"; url=url+"?projectCode="+prj.options[prj.selectedIndex].value; xmlhttp.onreadystatechange=stateChanged; xmlhttp.open("GET",url,true); xmlhttp.send(null); and then in responsexml.jsp I do like that: <% String projectcode= (String)request.getParameter("projectCode"); System.out.println("++++projectCode:=" +projectcode); Session s = null; Transaction tx; try { s = HibernateUtil.currentSession(); tx = s.beginTransaction(); Query query = s.createQuery("SELECT from Wa wa where wa.ProjectCode='"+projectcode+"'"); response.setContentType("text/xml"); PrintWriter output = response.getWriter(); output.write( "<?xml version=\"1.0\" encoding=\"utf-8\"?>"); //response.setHeader("Cache-Control", "no-cache"); //constriure le xml if(projectcode!=null) { for(Iterator it=query.iterate();it.hasNext();) { if(it.hasNext()) { Wa object=(Wa)it.next(); //out.print( "<item id=\"" +object.getIdWA() + "\" name=\"" + object.getWAName() + "\" />"); output.write("<wa>"); output.write( "<item id=\"" + object.getIdWA() + "\" name=\"" + object.getWAName() + "\" />"); output.write("</wa>"); } } } } catch (HibernateException e) { e.printStackTrace(); } %> </body> </html> With this code I dont have my xml file. I got this error: The server did not understand the request, or the request was invalid. Erreur de traitement de la ressource http://www.w3.o... PLEASE HELP.

    Read the article

  • NSFormatter problem: not getting called for the empty string

    - by Enchilada
    I have created a custom formatter for my (read-only) table column. It looks like this: - (NSString *)stringForObjectValue:(id)anObject { NSAssert([anObject isKindOfClass:[NSString class]] && anObject != nil, @"invalid object"); if ([anObject isEqualToString:@""]) return @"EMPTY"; else return [anObject stringByAppendingString:@"++"]; } Very simple. The corresponding objects are just strings, so it's an string-to-string formatter. All non-empty string objects are returned with @"++" appended to them. Empty string objects should be turned into the @"EMPTY" string. The @"++" gets appended to non-empty strings just fine. The problem is, @"EMPTY" never gets shown! My formatter is never called by Cocoa when the underlying object is the empty string. The corresponding row just keeps being empty, instead of showing my requested @"EMPTY". Any ideas?

    Read the article

  • Java MySQL Query Problem MySQLSyntaxErrorException When Creating a Table

    - by Aqib Mushtaq
    I fairly new to MySQL with Java, but I have executed a few successful INSERT queries however cannot seem to get the CREATE TABLE query to execute without getting the 'MySQLSyntaxErrorException' exception. My code is as follows: import java.sql.*; Statement stmt; Class.forName("com.mysql.jdbc.Driver"); String url = "jdbc:mysql://localhost:3306/mysql"; Connection con = DriverManager.getConnection(url, "root", "password"); stmt = con.createStatement(); String tblSQL = "CREATE TABLE IF NOT EXISTS \'dev\'.\'testTable\' (\n" + " \'id\' int(11) NOT NULL AUTO_INCREMENT,\n" + " \'date\' smallint(6) NOT NULL\n" + ") ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;"; stmt.executeUpdate(tblSQL); stmt.close(); con.close(); And the error is as follows: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''dev'.'testTable' ( 'id' int(11) NOT NULL AUTO_INCREMENT, 'date' smallint(6) N' at line 1 I would appreciate it if anyone could spot the mistake in this query, as I've tried executing this within phpMyAdmin and it works as it should. Thanks in advance.

    Read the article

< Previous Page | 313 314 315 316 317 318 319 320 321 322 323 324  | Next Page >