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  • derby + hibernate ConstraintViolationException using manytomany relationships

    - by user364470
    Hi, I'm new to Hibernate+Derby... I've seen this issue mentioned throughout the google, but have not seen a proper resolution. This following code works fine with mysql, but when I try this on derby i get exceptions: ( each Tag has two sets of files and vise-versa - manytomany) Tags.java @Entity @Table(name="TAGS") public class Tags implements Serializable { @Id @GeneratedValue(strategy=GenerationType.AUTO) public long getId() { return id; } @ManyToMany(targetEntity=Files.class ) @ForeignKey(name="USER_TAGS_FILES",inverseName="USER_FILES_TAGS") @JoinTable(name="USERTAGS_FILES", joinColumns=@JoinColumn(name="TAGS_ID"), inverseJoinColumns=@JoinColumn(name="FILES_ID")) public Set<data.Files> getUserFiles() { return userFiles; } @ManyToMany(mappedBy="autoTags", targetEntity=data.Files.class) public Set<data.Files> getAutoFiles() { return autoFiles; } Files.java @Entity @Table(name="FILES") public class Files implements Serializable { @Id @GeneratedValue(strategy=GenerationType.AUTO) public long getId() { return id; } @ManyToMany(mappedBy="userFiles", targetEntity=data.Tags.class) public Set getUserTags() { return userTags; } @ManyToMany(targetEntity=Tags.class ) @ForeignKey(name="AUTO_FILES_TAGS",inverseName="AUTO_TAGS_FILES") @JoinTable(name="AUTOTAGS_FILES", joinColumns=@JoinColumn(name="FILES_ID"), inverseJoinColumns=@JoinColumn(name="TAGS_ID")) public Set getAutoTags() { return autoTags; } I add some data to the DB, but when running over Derby these exception turn up (the don't using mysql) Exceptions SEVERE: DELETE on table 'FILES' caused a violation of foreign key constraint 'USER_FILES_TAGS' for key (3). The statement has been rolled back. Jun 10, 2010 9:49:52 AM org.hibernate.event.def.AbstractFlushingEventListener performExecutions SEVERE: Could not synchronize database state with session org.hibernate.exception.ConstraintViolationException: could not delete: [data.Files#3] at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:96) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.persister.entity.AbstractEntityPersister.delete(AbstractEntityPersister.java:2712) at org.hibernate.persister.entity.AbstractEntityPersister.delete(AbstractEntityPersister.java:2895) at org.hibernate.action.EntityDeleteAction.execute(EntityDeleteAction.java:97) at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:268) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:260) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:184) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1206) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:613) at org.hibernate.context.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:344) at $Proxy13.flush(Unknown Source) at data.HibernateORM.removeFile(HibernateORM.java:285) at data.DataImp.removeFile(DataImp.java:195) at booting.DemoBootForTestUntilTestClassesExist.main(DemoBootForTestUntilTestClassesExist.java:62) I have never used derby before so maybe there is something crutal that i'm missing 1) what am I doing wrong? 2) is there any way of cascading properly when I have 2 many-to-many relationships between two classes? Thanks!

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  • Switching to a VPS

    - by Damian
    Well, I know absolutely nothing about the subject, so I really need help. I currently have a website running on google app-engine (Java) and I can't get it to what I want because of app engine's limitations (no full text search mainly). The traffic is low, never reached 15% of the free quota (around 1500 daily pageviews). I also have 3 sites in drupal hosted in a shared hosting service, and this is giving me problems, because the server speed is awful. The sites are VERY low trafic, but load times are bad, and I might need to add more sites for some clients, so this will only get worse. So, i'm planning to move all that to VPS. The question is, can I have 2 http servers running in the same VPS? because I will need Apache-php-drupal server and a java server (tomcat?). I have really no idea on this, so any tip will be very helpful to me. Thanks!

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  • Why do mainframe greybeards refer to DB2/zOS as "he"? [closed]

    - by Alex Nauda
    If you ask a DB2/zOS engine DBA a question about DB2's behavior, the DBA will refer to the DB2 engine as "he" much the way a sailor uses "she" to refer to his ship. For example: "Once you fill the freespace, DB2 still wants to keep those rows in cluster order in the tablespace. That's why he'll split that page in half, and you end up with lots of half-empty pages. That is, unless the cluster key of the row you've just inserted is the highest in the table, in which case he makes a new empty page, and he puts just your new row into that page. So I wouldn't have to do this REORG if you would just sort your input like I suggested." Does anyone know where this tradition comes from?

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  • Grails Duplicate Exception handling

    - by Srinath
    Hi, How to catch duplicate key exceptions in Grails . when trying to save existing integer for a unique column constraint, the error is generating while saving/updating a record . Also used try{ object.save(flush:true) }catch(org.springframework. dao.DataIntegrityViolationException e){ println e.message }catch(org.hibernate.exception.ConstraintViolationException ex){ println e.message }catch(Exception e){ println e.message } But unable to catch this issue . 23:41:13,265 ERROR [JDBCExceptionReporter:101] Duplicate entry '1' for key 2 23:41:13,281 ERROR [AbstractFlushingEventListener:324] Could not synchronize database state with session org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:94) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:275) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:168) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027) Could you please share the solution to solve this .

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  • I am not able to drop foreign key in mysql Error 150. Please help

    - by Shantanu Gupta
    i am trying to create a foreign key in my table. But when i executes my query it shows me error 150 Error Code : 1005 Can't create table '.\vts#sql-6ec_1.frm' (errno: 150) (0 ms taken) My Queries are Query to create a foreign Key alter table `vts`.`tblguardian` add constraint `FK_tblguardian` FOREIGN KEY (`GuardianPickPointId`) REFERENCES `tblpickpoint` (`PickPointId`) EDIT: Now I am trying to drop this constraint But it fails again and shows me same error as it was giving when i was trying to create foreign key. alter table `vts`.`tblguardian` drop index `FK_tblguardian` Primary Key table CREATE TABLE `tblpickpoint` ( `PickPointId` int(4) NOT NULL auto_increment, `PickPointName` varchar(500) default NULL, `PickPointLabel` varchar(500) default NULL, `PickPointLatLong` varchar(100) NOT NULL, PRIMARY KEY (`PickPointId`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 CHECKSUM=1 DELAY_KEY_WRITE=1 ROW_FORMAT=DYNAMIC Foreign Key Table CREATE TABLE `tblguardian` ( `GuardianId` int(4) NOT NULL auto_increment, `GuardianName` varchar(500) default NULL, `GuardianAddress` varchar(500) default NULL, `GuardianMobilePrimary` varchar(15) NOT NULL, `GuardianMobileSecondary` varchar(15) default NULL, `GuardianPickPointId` int(4) default NULL, PRIMARY KEY (`GuardianId`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1

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  • QML 5.3 iOS compilation of pure QML app

    - by Nathaniel Johnson
    I have an application written in QML. Initially, I used the standard C++ bootstrap for the app. int main(int argc, char *argv[]) { QApplication app(argc, argv); // A bunch of components and data models written in C++ QQmlApplicationEngine engine; engine.load(QUrl(QStringLiteral("qrc:///main.qml"))); return app.exec(); } The bulk of the app is in QML and the more I work with QML, the happier I am with it and the more I feel comfortable converting the C++ pieces to QML. So, it comes to one risk that I wanted to ask about. If I convert the app to a pure QML application like the kind generated by the Qt Quick UI application wizard with no C++ and designed to be run with qmlscene will I be able to compile it for iOS when the time to port it comes or will I end up just converting it back to the C++ loader form? TL;DR Can pure QML (no C++) apps be compiled and run on iOS devices?

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  • Javascript does not work on IIS

    - by Cat Mitch
    I have a .NET library executing as part of our website that renders HTML to image formats. It uses the IE rendering engine, and will happily run any javascript if present to do the rendering. The problem is we just moved the code to a new server, and javascript seems to be disabled. I tried changing (briefly the Application Pools Process Model Identity from NetworkService to LocalSystem, and that worked fine. Hence it must be a permissions problem. So my questions are this: 1) What is the specific permission I need to set to allow the IE rendering engine to execute javascript, inside the IIS application pool? 2) What is the best way to enable that in my application pool? Do I just somehow set it in NetworkService, or create a new identify (how is that done?) Thanks!

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  • Is it possible to have an out-of-process COM server where a separate O/S process is used for each ob

    - by Tom Williams
    I have a legacy C++ "solution engine" that I have already wrapped as an in-process COM object for use by client applications that only require a single "solution engine". However I now have a client application that requires multiple "solution engines". Unfortunately the underlying legacy code has enough global data, singletons and threading horrors that given available resources it isn't possible to have multiple instances of it in-process simultaneously. What I am hoping is that some kind soul can tell me of some COM magic where with the flip of a couple of registry settings it is possible to have a separate out-of-process COM server (separate operating system process) for each instance of the COM object requested. Am I in luck?

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  • VS compiling Error 1256 ( integer overflow in internal computation ... ) during inheritance

    - by odbb
    Hi there, my problem occurs during compiling Irrlicht3D Engine in VS 2008. 1Error 1256: integer overflow in internal computation due to size or complexity of "irr::IReferenceCounted" I'm currently merging a very old Softwaredriver I have written with the rest of the engine which is much newer. The main Problme is that I have tried to resolve abstract inherince problems. But now I get this error and it is the only one. "irr::IReferenceCounted" is one of the base classes used by other classes which have been inherinced from. What does that mean? I know that an integer overflow can be a normal overflow, but why is this shown during compilation? Any help appreciated! -db

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  • Howto access thread data outside a thread

    - by Quandary
    Question: I start the MS Text-to-speech engine in a thread, in order to avoid a crash on DLL_attach. It starts fine, and the text to speech engine gets initialized, but I can't access ISpVoice outside the thread. How can I access ISpVoice outside the thread ? It's a global variable after all... #include <windows.h> #include <sapi.h> #include "XPThreads.h" ISpVoice * pVoice = NULL; unsigned long init_engine_thread(void* param) { Sleep(5000); printf("lolthread\n"); //HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED); HRESULT hr = CoInitialize(NULL); if(FAILED(hr) ) { MessageBox(NULL, TEXT("Failed To Initialize"), TEXT("Error"), 0); char buffer[2000] ; sprintf(buffer, "An error occured: 0x%08X.\n", hr); FILE * pFile = fopen ( "c:\\temp\\CoInitialize_dll.txt" , "w" ); fwrite (buffer , 1 , strlen(buffer) , pFile ); fclose (pFile); } else { printf("trying to create instance.\n"); //HRESULT hr = CoCreateInstance(CLSID_SpVoice, NULL, CLSCTX_ALL, IID_ISpVoice, (void **) &pVoice); //hr = CoCreateInstance(CLSID_SpVoice, NULL, CLSCTX_ALL, IID_ISpVoice, (void **) &pVoice); //HRESULT hr = CoCreateInstance(__uuidof(ISpVoice), NULL, CLSCTX_INPROC_SERVER, IID_ISpVoice, (void **) &pVoice); HRESULT hr = CoCreateInstance(__uuidof(SpVoice), NULL, CLSCTX_ALL, IID_ISpVoice, (void **) &pVoice); if( SUCCEEDED( hr ) ) { printf("Succeeded\n"); hr = pVoice->Speak(L"The text to speech engine has been successfully initialized.", 0, NULL); } else { printf("failed\n"); MessageBox(NULL, TEXT("Failed To Create COM instance"), TEXT("Error"), 0); char buffer[2000] ; sprintf(buffer, "An error occured: 0x%08X.\n", hr); FILE * pFile = fopen ( "c:\\temp\\CoCreateInstance_dll.txt" , "w" ); fwrite (buffer , 1 , strlen(buffer) , pFile ); fclose (pFile); } } if(pVoice != NULL) { pVoice->Release(); pVoice = NULL; } CoUninitialize(); return NULL; } XPThreads* ptrThread = new XPThreads(init_engine_thread); BOOL APIENTRY DllMain( HMODULE hModule, DWORD ul_reason_for_call, LPVOID lpReserved) { switch (ul_reason_for_call) { case DLL_PROCESS_ATTACH: //init_engine(); LoadLibrary(TEXT("ole32.dll")); ptrThread->Run(); break; case DLL_THREAD_ATTACH: break; case DLL_THREAD_DETACH: break; case DLL_PROCESS_DETACH: break; } return TRUE; }

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  • Unable to relate two MySQL tables (foreign keys)

    - by KPL
    Hello people, Here's my USER table CREATE TABLE IF NOT EXISTS `users` ( `id` int(11) NOT NULL AUTO_INCREMENT, `username` varchar(100) NOT NULL, `expiry` varchar(6) NOT NULL, `contact_id` int(11) NOT NULL, `email` varchar(255) NOT NULL, `password` varchar(100) NOT NULL, `level` int(3) NOT NULL, `active` tinyint(4) NOT NULL DEFAULT '1', PRIMARY KEY (`id`,`email`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ; And here's my contact_info table CREATE TABLE IF NOT EXISTS `contact_info` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) NOT NULL, `email_address` varchar(255) NOT NULL, `company_name` varchar(255) NOT NULL, `license_number` varchar(255) NOT NULL, `phone` varchar(30) NOT NULL, `fax` varchar(30) NOT NULL, `mobile` varchar(30) NOT NULL, `category` varchar(100) NOT NULL, `country` varchar(20) NOT NULL, `state` varchar(20) NOT NULL, `city` varchar(100) NOT NULL, `postcode` varchar(50) NOT NULL, PRIMARY KEY (`id`,`email_address`), ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ; The system uses username to login users.I want to modify it in such a way that it uses email for login. But there's no email_address in users table. I have added foreign key - email in user table(which is email_address in contact_info). How should I query database?

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  • Sqlalchemy layout with WSGI application

    - by TheDude
    I'm working on writing a small WSGI application using Bottle and SqlAlchemy and am confused on how the "layout" of my application should be in terms of SqlAlchemy. My confusion is with creating engines and sessions. My understanding is that I should only create one engine with the 'create_engine' method. Should I be creating an engine instance in the global namespace in some sort of singleton pattern and creating sessions based off of it? How have you done this in your projects? Any insight would be appreciated. The examples in the documentation dont seem to make this entirely clear (unless I'm missing something obvious). Any thoughts?

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  • What is the meanning of 'idx_categories_desc_categories_name' in osCommerce

    - by Sumant
    while working on osCommerce-3 i got the table structure for category & categories_description as CREATE TABLE IF NOT EXISTS `osc_categories` ( `categories_id` int(10) unsigned NOT NULL AUTO_INCREMENT, `categories_image` varchar(255) DEFAULT NULL, `parent_id` int(10) unsigned DEFAULT NULL, `sort_order` int(11) DEFAULT NULL, `date_added` datetime DEFAULT NULL, `last_modified` datetime DEFAULT NULL, PRIMARY KEY (`categories_id`), KEY `idx_categories_parent_id` (`parent_id`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=5 ; CREATE TABLE IF NOT EXISTS `osc_categories_description` ( `categories_id` int(10) unsigned NOT NULL, `language_id` int(10) unsigned NOT NULL, `categories_name` varchar(255) NOT NULL, PRIMARY KEY (`categories_id`,`language_id`), KEY `idx_categories_desc_categories_id` (`categories_id`), KEY `idx_categories_desc_language_id` (`language_id`), KEY `idx_categories_desc_categories_name` (`categories_name`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8; here i am not getting the meanning of indexing "idx_categories_desc_categories_id", "idx_categories_desc_language_id", "idx_categories_desc_categories_name" What is the use of this indexing.What does it mean?

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  • Connect 4 with neural network: evaluation of draft + further steps

    - by user89818
    I would like to build a Connect 4 engine which works using an artificial neural network - just because I'm fascinated by ANNs. I'be created the following draft of the ANN structure. Would it work? And are these connections right (even the cross ones)? Could you help me to draft up an UML class diagram for this ANN? I want to give the board representation to the ANN as its input. And the output should be the move to chose. The learning should later be done using backpropagation and the sigmoid function should be applied. The engine will play against human players. And depending on the result of the game, the weights should be adjusted then.

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  • Sphinx + tokyo Tyrant + mysql

    - by stunti
    I'm looking at creating a full text search engine for one of my projects. We have a Mysql, Tokyo Tyrant and file documents that need to be indexed. I'm looking at Sphinx right now but I can't figured out if I can use it to index every document. I know it's possible to let Sphinx to use Mysql but I'm looking at a way to let Sphinx index and query Tokyo Tyrant as well as index file documents. It could be Sphinx or Xapian or another one but no JAVA (Lucene is out) but something that can be used with PHP and run on Linux. Any idea of a search engine that can accept more that Mysql as the source? Thanks

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  • MySQL forgot about automatically creating an index for a foreign key?

    - by bobo
    After running the following SQL statements, you will see that, MySQL has automatically created the non-unique index question_tag_tag_id_tag_id on the tag_id column for me after the first ALTER TABLE statement has run. But after the second ALTER TABLE statement has run, I think MySQL should also automatically create another non-unique index question_tag_question_id_question_id on the question_id column for me. But as you can see from the SHOW INDEXES statement output, it's not there. Why does MySQL forget about the second ALTER TABLE statement? By the way, since I have already created a unique index question_id_tag_id_idx used by both question_id and tag_id columns. Is creating a separate index for each of them redundant? mysql> DROP DATABASE mydatabase; Query OK, 1 row affected (0.00 sec) mysql> CREATE DATABASE mydatabase; Query OK, 1 row affected (0.00 sec) mysql> USE mydatabase; Database changed mysql> CREATE TABLE question (id BIGINT AUTO_INCREMENT, html TEXT, PRIMARY KEY(id)) ENGINE = INNODB; Query OK, 0 rows affected (0.05 sec) mysql> CREATE TABLE tag (id BIGINT AUTO_INCREMENT, name VARCHAR(10) NOT NULL, UNIQUE INDEX name_idx (name), PRIMARY KEY(id)) ENGINE = INNODB; Query OK, 0 rows affected (0.05 sec) mysql> CREATE TABLE question_tag (question_id BIGINT, tag_id BIGINT, UNIQUE INDEX question_id_tag_id_idx (question_id, tag_id), PRIMARY KEY(question_id, tag_id)) ENGINE = INNODB; Query OK, 0 rows affected (0.00 sec) mysql> ALTER TABLE question_tag ADD CONSTRAINT question_tag_tag_id_tag_id FOREIGN KEY (tag_id) REFERENCES tag(id); Query OK, 0 rows affected (0.10 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> ALTER TABLE question_tag ADD CONSTRAINT question_tag_question_id_question_id FOREIGN KEY (question_id) REFERENCES question(id); Query OK, 0 rows affected (0.13 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> SHOW INDEXES FROM question_tag; +--------------+------------+----------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | +--------------+------------+----------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ | question_tag | 0 | PRIMARY | 1 | question_id | A | 0 | NULL | NULL | | BTREE | | | question_tag | 0 | PRIMARY | 2 | tag_id | A | 0 | NULL | NULL | | BTREE | | | question_tag | 0 | question_id_tag_id_idx | 1 | question_id | A | 0 | NULL | NULL | | BTREE | | | question_tag | 0 | question_id_tag_id_idx | 2 | tag_id | A | 0 | NULL | NULL | | BTREE | | | question_tag | 1 | question_tag_tag_id_tag_id | 1 | tag_id | A | 0 | NULL | NULL | | BTREE | | +--------------+------------+----------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ 5 rows in set (0.01 sec) mysql>

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  • What Database to distribute as part of a C# app backend

    - by jez
    I am planning on writing and commercialising a C# app which will store data in an underlying database I use MySQL on my environment for my own development and this is what I would have used to write the application for myself (no need to use FK - MyISAM engine would be fine). I am concerned about how easy it will be to distribute the app together with the database engine. Would using MySQL allow me for easy packaging of the app for a "one-click" install on the client side? (ie I do not want them to have to install MySQL by themselves) and also is it feasible from a licensing point of view? Are there other Database systems which would make the process more straight-forward

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  • Precise explanation of JavaScript <-> DOM circular reference issue

    - by Joey Adams
    One of the touted advantages of jQuery.data versus raw expando properties (arbitrary attributes you can assign to DOM nodes) is that jQuery.data is "safe from circular references and therefore free from memory leaks". An article from Google titled "Optimizing JavaScript code" goes into more detail: The most common memory leaks for web applications involve circular references between the JavaScript script engine and the browsers' C++ objects' implementing the DOM (e.g. between the JavaScript script engine and Internet Explorer's COM infrastructure, or between the JavaScript engine and Firefox XPCOM infrastructure). It lists two examples of circular reference patterns: DOM element → event handler → closure scope → DOM DOM element → via expando → intermediary object → DOM element However, if a reference cycle between a DOM node and a JavaScript object produces a memory leak, doesn't this mean that any non-trivial event handler (e.g. onclick) will produce such a leak? I don't see how it's even possible for an event handler to avoid a reference cycle, because the way I see it: The DOM element references the event handler. The event handler references the DOM (either directly or indirectly). In any case, it's almost impossible to avoid referencing window in any interesting event handler, short of writing a setInterval loop that reads actions from a global queue. Can someone provide a precise explanation of the JavaScript ↔ DOM circular reference problem? Things I'd like clarified: What browsers are effected? A comment in the jQuery source specifically mentions IE6-7, but the Google article suggests Firefox is also affected. Are expando properties and event handlers somehow different concerning memory leaks? Or are both of these code snippets susceptible to the same kind of memory leak? // Create an expando that references to its own element. var elem = document.getElementById('foo'); elem.myself = elem; // Create an event handler that references its own element. var elem = document.getElementById('foo'); elem.onclick = function() { elem.style.display = 'none'; }; If a page leaks memory due to a circular reference, does the leak persist until the entire browser application is closed, or is the memory freed when the window/tab is closed?

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  • Object validator - is this good design?

    - by neo2862
    I'm working on a project where the API methods I write have to return different "views" of domain objects, like this: namespace View.Product { public class SearchResult : View { public string Name { get; set; } public decimal Price { get; set; } } public class Profile : View { public string Name { get; set; } public decimal Price { get; set; } [UseValidationRuleset("FreeText")] public string Description { get; set; } [SuppressValidation] public string Comment { get; set; } } } These are also the arguments of setter methods in the API which have to be validated before storing them in the DB. I wrote an object validator that lets the user define validation rulesets in an XML file and checks if an object conforms to those rules: [Validatable] public class View { [SuppressValidation] public ValidationError[] ValidationErrors { get { return Validator.Validate(this); } } } public static class Validator { private static Dictionary<string, Ruleset> Rulesets; static Validator() { // read rulesets from xml } public static ValidationError[] Validate(object obj) { // check if obj is decorated with ValidatableAttribute // if not, return an empty array (successful validation) // iterate over the properties of obj // - if the property is decorated with SuppressValidationAttribute, // continue // - if it is decorated with UseValidationRulesetAttribute, // use the ruleset specified to call // Validate(object value, string rulesetName, string FieldName) // - otherwise, get the name of the property using reflection and // use that as the ruleset name } private static List<ValidationError> Validate(object obj, string fieldName, string rulesetName) { // check if the ruleset exists, if not, throw exception // call the ruleset's Validate method and return the results } } public class Ruleset { public Type Type { get; set; } public Rule[] Rules { get; set; } public List<ValidationError> Validate(object property, string propertyName) { // check if property is of type Type // if not, throw exception // iterate over the Rules and call their Validate methods // return a list of their return values } } public abstract class Rule { public Type Type { get; protected set; } public abstract ValidationError Validate(object value, string propertyName); } public class StringRegexRule : Rule { public string Regex { get; set; } public StringRegexRule() { Type = typeof(string); } public override ValidationError Validate(object value, string propertyName) { // see if Regex matches value and return // null or a ValidationError } } Phew... Thanks for reading all of this. I've already implemented it and it works nicely, and I'm planning to extend it to validate the contents of IEnumerable fields and other fields that are Validatable. What I'm particularly concerned about is that if no ruleset is specified, the validator tries to use the name of the property as the ruleset name. (If you don't want that behavior, you can use [SuppressValidation].) This makes the code much less cluttered (no need to use [UseValidationRuleset("something")] on every single property) but it somehow doesn't feel right. I can't decide if it's awful or awesome. What do you think? Any suggestions on the other parts of this design are welcome too. I'm not very experienced and I'm grateful for any help. Also, is "Validatable" a good name? To me, it sounds pretty weird but I'm not a native English speaker.

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  • Connect to Oracle database on a different server from PHP

    - by macha
    Hello I have a database engine sitting on a remote server, while my webserver is present locally. I have worked pretty much with client-server architecture, where the server has both the webserver and the database engine. Now I need to connect to an Oracle database which is situated on a different server. Can anybody give me any suggestions?? I believe ODBC_CONNECT might not work. Do I use OCI8 drivers?? How would I connect to my database server. Also I would have a very high number of database calls going back and forth, so is it good to go with persistent connection or do I still use individual database calls?

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  • InnoDB not supported by webhost. What now?

    - by Peter Perhác
    I was developing a small WAMP web application on my laptop, where I have an instance of mySQL running and I chose InnoDB for my DB engine. After several weeks' development I wanted to make it available to the public and found out the database server provided by my web host does not support InnoDB, only MyISAM. The create-and-populate script generated from the innoDB schema on my laptop, when executed against the live database, can manage to create individual TABLES but then runs into problems creating the VIEWs. Are views not supported in MyISAM? I know FOREIGN KEYs are not. That's very much why I made the choice of InnoDB... What are my chances of making my innoDB schema design work with myISAM? Is there any straightforward way of converting the whole schema from one storage engine to the other? Should I look for another web host that does provide a mysql db that supports innoDB?

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  • SubSonic isn't generating MySql foreign key tables

    - by keith
    I two tables within a MySql 5.1.34 database. When using SubSonic to generate the DAL, the foreign-key relationship doesn't get scripted, ie; I have no Parent.ChildCollection object. Looking inside the generated DAL Parent class shows the following; //no foreign key tables defined (0) I have tried SubSonic 2.1 and 2.2, and various MySql 5 versions. I must be doing something wrong procedurally - any help would be greatly appreciated. This has always just worked 'out-the-box' when using MS-SQL. TABLE `parent` ( `ParentId` INT(11) NOT NULL AUTO_INCREMENT, `SomeData` VARCHAR(25) DEFAULT NULL, PRIMARY KEY (`ParentId`) ) ENGINE=INNODB DEFAULT CHARSET=latin1; TABLE `child` ( `ChildId` INT(11) NOT NULL AUTO_INCREMENT, `ParentId` INT(11) NOT NULL, `SomeData` VARCHAR(25) DEFAULT NULL, PRIMARY KEY (`ChildId`), KEY `FK_child` (`ParentId`), CONSTRAINT `FK_child` FOREIGN KEY (`ParentId`) REFERENCES `parent` (`ParentId`) ) ENGINE=INNODB DEFAULT CHARSET=latin1;

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  • C# Script version of PyBinding for WPF

    - by Jim Strav
    I wrote a CSharpScriptBinding roughly equivalent to the PyBinding on CodePlex. It uses the C# script engine from http://www.csscript.net. After I wrote it, I kind of decided it might not really be something good to use. Although it caches the compiled script code as an already compiled Assembly, my concern is that I will have one temporary Assembly created each time I use the binding. Will this add up to a problem in the future? If so, maybe there is a way in the C# script engine that I don't know about to optimize this further...? Any thoughts to confirm my suspicion that this was just a bad idea (but useful excersise in learning more about bindings and converters)?

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  • Using a set of numbers inside a database without creating a temporary table

    - by Zizzencs
    I have a set of numbers and a table in a database with the id (primary key) and text (not null) columns. I would like to create a query that returns all the numbers in the set and the associated text from the table. Unfortunately not all numbers exist in the database's id column, so this won't work: select id, text from table where id in (<set of numbers>) For the non-existing ids the best would be to return null as the text from the query. Is there a way to produce the desired output without first creating a temporary table from the set inside the database? The database engine in use is a Microsoft SQL Server 2008 SP1 but I'd be interested in any solution with any database engine.

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