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  • question on database query using hibernate in java with annotations

    - by molleman
    Hello, simple question regarding HQL(Hibernate query language) so i have user class , that can hold a list of Projects, how do i take this out of the database depending on a username, this is how i take out my user String username = "stephen"; YFUser user = (YFUser) session.createQuery("select u FROM YFUser u where u.username = :username").setParameter("username", name).uniqueResult(); but i want to take out the list of projects here is the projects list within the class YFUser(my user class); how would i query the database to get this list of projects @Entity @Table(name = "yf_user_table") public class YFUser implements Serializable,ILightEntity { ......... @OneToMany(cascade = CascadeType.ALL,fetch = FetchType.LAZY) @JoinTable(name = "YFUSER_JOIN_PROJECT", joinColumns = { @JoinColumn(name = "user_id") }, inverseJoinColumns = { @JoinColumn(name = "project_id") }) private List<Project> projects = new ArrayList<Project>();

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  • Where to open sessions in a Spring/Hibernate stack?

    - by CaptainAwesomePants
    I'm trying to figure out a good design for a Spring/Hibernate app. When creating such an app, it appears like there are a handful of major decisions. The first major decision seems to be where to put the session/transaction boundary. It seems like I have 3 major choices: as a filter before controllers are even invoked, immediately below the controllers at the service call level, and stuffed way below the business level in repository calls. It seems to me like the right call is the middle path, but I'm not sure. I don't want my transactions open too long, but at the same time, I don't want to constantly worry about detached objects and lazy loading in the business logic. Still, there are some downsides. For instance, it makes it hard for the business logic to make a remote call without holding up a transaction for a few seconds. I wonder if there's a better way?

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  • DebuggerDisplay attribute does not work as expected!

    - by mark
    Dear ladies and sirs. I know that this attribute should work in C# and yet, in my case it does not. I have a class with a lazy property Children. Accessing this property may have a side effect of roundtripping to the server. So, naturally, I do not want this to happen when I just watch it in the debugger watch window. Omitting all the irrelevant details the source looks pretty ordinary: [DebuggerDisplay("(Frozen) {m_children}")] public IList<IEntityBase> Children { get { if (m_children == null) { m_children = FetchChildrenFromDB(this); } return m_children; } } And yet, when I watch the object and expand this in the watch window I do not see (Frozen) in the display, meaning the debugger simply ignores the attribute. Provided the image link is still valid it should be visible below: http://i28.tinypic.com/2zxo9s5.jpg The attribute is really there, according to Reflector. I use VS2008. Any ideas?

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  • Table and column naming conventions when plural and singular forms are odd or the same

    - by Superstringcheese
    In my search I found mostly arguments for whether to use plurality in database naming conventions, and ways to handle it in either case. I have decided I prefer plural table names, so I don't want to argue that. I need to represent an animal's species and genus and so on in a database. The plural and singular form for 'species' are the same, and the plural of 'genus' is 'genera'. I think I can get by with: Table: Genera | Column: Genus But I'm unsure how I should handle: Table: Species | Column: Species If I really wanted to be lazy about this I'd just name them 'species specie' and 'genuses genus', but I would prefer to read them in their correct forms. Any advice would be appreciated.

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  • Editing Multiple files in vi with Wildcards

    - by Alan Storm
    When using the programmers text editor vi, I'll often using a wildcard search to be lazy about the file I want to edit vi ThisIsAReallLongFi*.txt When this matches a single file it works great. However, if it matches multiple files vi does something weird. First, it opens the first file for editing Second, when I :wq out of the file, I get a message the bottom of the terminal that looks like this E173: 4 more files to edit Hit ENTER or type command to continue When I hit enter, it returns me to edit mode in the file I was just in. The behavior I'd expect here would be that vi would move on to the next file to edit. So, What's the logic behind vi's behavior here Is there a way to move on and edit the next file that's been matched? And yes, I know about tab completion, this question is based on curiosity and wanting to understand the shell better.

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  • What is a good Very-High level UI framework for JavaScript?

    - by Robert Gould
    I need to write a temporary Web-based graphical front-end for a custom server system. In this case performance and scalability aren't issues, since at most 10 people may check the system simultaneously. Also it should be PHP or Python (server) & JavaScript (client) (can't use Flex or Silverlight for very specific non-programming related issues). So I know I could use YUI or jQuery, but was wondering if there is something even more high-level that would say allow me to write such a little project within a few hours of work, and get done with it. Basically I want to be as lazy as possible (this is throw-away code anyways) and get the job done in as little time as possible. Any suggestions?

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  • jQuery TriggerHandler doesn't trigger keyup event set via live

    - by Beck
    Why i can't trigget handler via triggerHandler if it's was bound via live? For example form.find('#code').live('change keyup',function(){ process_code($(this)); }); Startups after window load: /* Triggers */ if(checkCookie('banner_ready_code')) { $('#form').find('#code').triggerHandler('keyup'); } Nothing happens... If i'm binding simply by .change or .keyup, triggerHandler is working properly as intended. If it's bug, where to report it. Too lazy :) If not, please explain. :)

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  • Paging in ActiveRecord

    - by Alex
    Does CastleProject ActiveRecord support paging? I need to load only data which is now seen on the screen. If I use [HasMany], it will be loaded as a whole either immediately or at the first call (if lazy attribute is true). However I only need something like first 100 records (then maybe 100 next records). Another question is how to load only 100 items. If the collection is too big, memory can reach its limit if we constantly load more and more items.

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  • Is it possible to exclude some files from checkin (TFS) ?

    - by Thomas Wanner
    We use configuration files within various projects under source control (TFS), where each developer has to make some adjustments in his local copy to configure his environment. The build process takes care about replacing the config files with the server configuration as a part of the deployment, so it doesn't actually matter what is in the repository. However, we would anyway like to keep some kind of a default non-breaking version of config files in the repository, so that e.g. people not involved in the particular project won't run into troubles because of local misconfiguration. We tried to resolve this by introducing the check-in policy that simply forbids to check-in the config files. This works fine, but just because we're lazy to always uncheck those checkboxes in the pending changes window, the question comes : is it possible to transparently disable the check-in of particular files without keeping them out of source control (e.g. locking their current version) ?

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  • Same table NHibernate mapping

    - by mircea .
    How can i go about defining a same table relation mapping (mappingbycode) using Nhibernate for instance let's say I have a class: public class Structure{ public int structureId; public string structureName; public Structure rootStructure; } that references the same class as rootStructure. mapper.Class<Structure>(m => { m.Lazy(true); m.Id(u => u.structureId, map => { map.Generator(Generators.Identity); }); m.Property(c => c.structureName); m.? // Same table mapping } ; Thanks

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  • Why does Java not have any destructor like C++?

    - by Abhishek Jain
    Java has its own garbage collection implementation so it does not require any destructor like C++ . This makes Java developer lazy in implementing memory management. And Garbage Collection is very expensive. Still we can have destructor along with garbage collector where developer can free resources and which can save garbage collector's work. This might improves the performance of application. Why does Java not provide any destructor kind of mechanism? Developer does not have control over GC but he/she can control or create object. Then why not give them ability to destruct the objects?

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  • ASP.NET MVC: run code after view has rendered (close db transaction)

    - by thermal7
    Hi, I am using ASP.NET MVC2 with NHibernate, but am facing an issue. All calls to the database via NHibernate should be inside a transaction, however code inside the view kicks off database calls in some instances. Thus there is a need to be able to commit the transaction after the view has rendered. For example displaying a list of users and their user roles you might show the user role using this code: <%: Model.UserRole.Name % This will cause a hit on the database as the UserRole is loaded using a NHibernate proxy. You can fetch the UserRole eagerly which circumvents the issue in this case, but there are cases where it is much faster to use lazy loading. Anyway, is there a way to run code after a view has rendered?

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  • Help me find some good 'Reflection' reading materials??

    - by IbrarMumtaz
    If it wasn't you guys I would've never discovered Albahari.com's free threading ebook. My apologies if I come off as being extremely lazy but I need to make efficient use of my time and make sure am not just swallowing any garbage of the web. Therefore I am looking for the best and most informative and with a fair bit of detail for the Reflection chapter in .Net. Reflection is something that comes up time and time again and I want to extend my reading from what I know already from the official 70-536 book. I'm not a big fan of MSDN but at the moment that's al I'm using. Anyone got any other good published reading material off the inter web that can help revision for the entrance exam??? Would be greatly appreciated !!! Thanks in Advance, Ibrar

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  • why does an event handler never gets called if its added within a loop on an ienumerable

    - by André Carvalho
    For instance: IEnumerable<MyType> list = someCollection.Select(i => new MyType(i)); foreach (var item in list) item.PropertyChanged += item_PropertyChanged; <-- this never gets called Bu if list is assigned like list = someCollection.Select(i => new MyType(i)).ToArray(); the event handler does get called.. Why? (i imagine it has something to do with the fact that a linq query is lazy, but the fact of looping through the result isn't enough??)

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  • Premature optimization is the root of all evil, but can it ever be too late?

    - by polygenelubricants
    "We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil" So what is that 3% like? Can the avoidance of premature optimization ever be taken too extreme that it does more harm than good? Even if it's rare, has there been a case of a real measurable software engineering disaster due to complete negligence to optimize early in the process? Bonus question: is software engineering pretty much the only field that has such a counter intuitive principle regarding doing something earlier rather than later before things potentially become too big a problem to fix? Personal question: how do you justify something as premature optimization and not just a case of you being lazy/ignorant/dumb?

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  • Is this ISession handled by the SessionScope - Castle ActiveRecord

    - by oillio
    Can I do this? I have the following in my code: public class ARClass : ActiveRecordBase<ARClass> { ---SNIP--- public void DoStuff() { using (new SessionScope()) { holder.CreateSession(typeof(ARClass)).Lock(this, LockMode.None); ...Do some work... } } } So, as I'm sure you can guess, I am doing this so that I can access lazy loaded references in the object. It works great, however I am worried about creating an ISession like this and just dropping it. Does it get properly registered with the SessionScope and will the scope properly tare my ISession down when it is disposed of? Or do I need to do more to manage it myself?

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  • How to make query on a property from a joined table in Hibernate using Criteria

    - by Palo
    Hello, I have the following mapping: <hibernate-mapping package="server.modules.stats.data"> <class name="User" table="user"> <id name="id"> <generator class="native"></generator> </id> <many-to-one name="address" column="addressId" unique="true" lazy="false" /> </class> <class name="Address" table="address"> <id name="id"> <generator class="native"></generator> </id> <property name="street" /> </class> </hibernate-mapping> How can I do a Criteria query to select all users living on some street? That is create Criteria query for this SQL: Select * from user join address on user.addressId = address.id where address.street='someStreet'

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  • Can we you the attached properties in C# class library?

    - by Manas Agarwal
    Hi I have implemented the Observer Pattern with lazy load. The class that requests the data from the database is a singleton class. Now I am able to load the data from one database (located in one datacenter) very easily. But I need to get the data from other data centers too and display on the same UI. I can somehow pass the address of second data center and fetch the data from there also. But once I will get the data from second data center, it will be added to earlier list only. So later it will be thought for me to distinguish between the data. So I thought of attaching a property with the result set, so that while displaying the output I can show the data for both the data centers separately but on the same UI. I thought of attached property as an option where I can attach the data center name with the list of the data obtained. How is it possible to do in C#? Thanks Manas

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  • Hierarchical Hibernate, how many queries are executed?

    - by ghost1
    So I've been dealing with a home brew DB framework that has some seriously flaws, the justification for use being that not using an ORM will save on the number of queries executed. If I'm selecting all possibile records from the top level of a joinable object hierarchy, how many separate calls to the DB will be made when using an ORM (such as Hibernate)? I feel like calling bullshit on this, as joinable entities should be brought down in one query , right? Am I missing something here? note: lazy initialization doesn't matter in this scenario as all records will be used.

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  • Autofac: Reference from a SingleInstance'd type to a HttpRequestScoped

    - by Michael Wagner
    I've got an application where a shared object needs a reference to a per-request object. Shared: Engine | Per Req: IExtensions() | Request If i try to inject the IExtensions directly into the constructor of Engine, even as Lazy(Of IExtension), I get a "No scope matching [Request] is visible from the scope in which the instance was requested." exception when it tries to instantiate each IExtension. How can I create a HttpRequestScoped instance and then inject it into a shared instance? Would it be considered good practice to set it in the Request's factory (and therefore inject Engine into RequestFactory)?

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  • Java Archtecture Decision !!

    - by santiagobasulto
    Hi everybody! I'm developing a medium Java app, and i'm facing a small problem due to my lack of expirience. I've a custom DAO, which gets "Article" objects from the DataBase. I've the Article class, and the DAO has a method called getArticle(int id), this method returns an Article. The Article has a Category object, and i'm using lazy loading. So, when i request for an Article Category (Article a = new Article(); a.getCategory();) the Article class gets the Category from the DAO and then returns it. I'm now thinking to cache it, so when i request multiple times to an Article's category, the database is only queried one time. My question is: where should i put that cache? I can put it on the Article class (in the DTO), or i can put it on the DAO class. What do you say? Thanks!

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  • Java DAO caching

    - by santiagobasulto
    I'm developing a medium Java app, and i'm facing a small problem due to my lack of experience. I've a custom DAO, which gets "Article" objects from the Database. I've the Article class, and the DAO has a method called getArticle(int id), this method returns an Article. The Article has a Category object, and I'm using lazy loading. So, when I request for an article's category (Article a = new Article(); a.getCategory();) the Article class gets the Category from the DAO and then returns it. I'm now thinking to cache it, so when I request multiple times to an article's category, the database is only queried one time. My question is: where should I put that cache? I can put it on the Article class (in the DTO), or I can put it on the DAO class. What do you say?

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  • hibernate versioning parent entity

    - by Priit
    Consider two entities Parent and Child. Child is part of Parent's transient collection Child has a ManyToOne mapping to parent with FetchType.LAZY Both are displayed on the same form to a user. When user saves the data we first update Parent instance and then Child collection (both using merge). Now comes the tricky part. When user modifies only Child property on the form then hibernate dirty checking does not update Parent instance and thus does not increase optimistic locking version number for that entity. I would like to see situation where only Parent is versioned and every time I call merge for Parent then version is always updated even if actual update is not executed in db.

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  • NHibernate, each property is filled with a different select statement

    - by Eitan
    I'm retrieving a list of nhibernate entites which have relationships to other tables/entities. I've noticed instead of NHibernate performing JOINS and populating the properties, it retrieves the entity and then calls a select for each property. For example if a user can have many roles and I retrieve a user from the DB, Nhibernate retrieves the user and then populates the roles with another select statement. The problem is that I want to retrieve oh let's say a list of products which have various many-to-many relationships and relationships to items which have their own relationships. In the end I'm left with over a thousand DB calls to retrieve a list of 30 products. Thanks. I've also set default lazy loading to false because whenever I save the list of entities to a session, I get an error when trying to retrieve it on another page: LazyInitializationException: could not initialize proxy If anybody could shed any light I would truly appreciate it. Thanks. Eitan

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