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  • Hibernate - get the size of a list in a property

    - by mada
    I have a class A which have a list of B elements. In my A class i would like to add: int size; which will be valued with the number of B elements. So when I would call myA.getSize() I will have it. Is it possible to map a count query with a single property in the hibernate mapping? I don't want to load the list that is why i would like to add a size property.

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  • How to access the backing field of an inherited class using fluent nhibernate

    - by Akk
    How do i set the Access Strategy in the mapping class to point to the inherited _photos field? public class Content { private IList<Photo> _photos; public Content() { _photos = new List<Photo>(); } public virtual IEnumerable<Photo> Photos { get { return _photos; } } public virtual void AddPhoto() {...} } public class Article : Content { public string Body {get; set;} } I am currently using thw following to try and locate the backing field but an exception is thrown as it cannot be found. public class ArticleMap : ClassMap<Article> { HasManyToMany(x => x.Photos) .Access.CamelCaseField(Prefix.Underscore) //_photos //... } i tried moving the backing field _photos directly into the class and the access works. So how can i access the backing field of an inherited class?

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  • Hibernate without primary keys generated by db?

    - by Michael Jones
    I'm building a data warehouse and want to use InfiniDB as the storage engine. However, it doesn't allow primary keys or foreign key constraints (or any constraints for that matter). Hibernate complains "The database returned no natively generated identity value" when I perform an insert. Each table is relational, and contains a unique integer column that was previously used as the primary key - I want to keep that, but just not have the constraint in the db that the column is the primary key. I'm assuming the problem is that Hibernate expects the db to return a generated key. Is it possible to override this behaviour so I can set the primary key field's value myself and keep Hibernate happy? -- edit -- Two of the mappings are as follows: <?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <!-- Generated Jun 1, 2010 2:49:51 PM by Hibernate Tools 3.2.1.GA --> <hibernate-mapping> <class name="com.example.project.Visitor" table="visitor" catalog="orwell"> <id name="id" type="java.lang.Long"> <column name="id" /> <generator class="identity" /> </id> <property name="firstSeen" type="timestamp"> <column name="first_seen" length="19" /> </property> <property name="lastSeen" type="timestamp"> <column name="last_seen" length="19" /> </property> <property name="sessionId" type="string"> <column name="session_id" length="26" unique="true" /> </property> <property name="userId" type="java.lang.Long"> <column name="user_id" /> </property> <set name="visits" inverse="true"> <key> <column name="visitor_id" /> </key> <one-to-many class="com.example.project.Visit" /> </set> </class> </hibernate-mapping> and: <?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <!-- Generated Jun 1, 2010 2:49:51 PM by Hibernate Tools 3.2.1.GA --> <hibernate-mapping> <class name="com.example.project.Visit" table="visit" catalog="orwell"> <id name="id" type="java.lang.Long"> <column name="id" /> <generator class="identity" /> </id> <many-to-one name="visitor" class="com.example.project.Visitor" fetch="join" cascade="all"> <column name="visitor_id" /> </many-to-one> <property name="visitId" type="string"> <column name="visit_id" length="20" unique="true" /> </property> <property name="startTime" type="timestamp"> <column name="start_time" length="19" /> </property> <property name="endTime" type="timestamp"> <column name="end_time" length="19" /> </property> <property name="userAgent" type="string"> <column name="user_agent" length="65535" /> </property> <set name="pageViews" inverse="true"> <key> <column name="visit_id" /> </key> <one-to-many class="com.example.project.PageView" /> </set> </class> </hibernate-mapping>

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  • @OneToOne and @JoinColumn, auto delete null entity , doable?

    - by smallufo
    I have two Entities , with the following JPA annotations : @Entity @Table(name = "Owner") public class Owner implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "id") private long id; @OneToOne(fetch=FetchType.EAGER , cascade=CascadeType.ALL) @JoinColumn(name="Data_id") private Data Data; } @Entity @Table(name = "Data") public class Data implements Serializable { @Id private long id; } Owner and Data has one-to-one mapping , the owning side is Owner. The problem occurs when I execute : owner.setData(null) ; ownerDao.update(owner) ; The "Owner" table's Data_id becomes null , that's correct. But the "Data" row is not deleted automatically. I have to write another DataDao , and another service layer to wrap the two actions ( ownerDao.update(owner) ; dataDao.delete(data); ) Is it possible to make a data row automatically deleted when the owning Owner set it to null ?

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  • Hibernate bug using Oracle?

    - by Lothar
    Hello, I've got the problem, that I use a property in the persistence.xml which forces Hibernate to look only for tables in the given schema. <property name="hibernate.default_schema" value="FOO"/> Because we are using now 4 different schemas the actual solution is to generate 4 war files with a modified persistence.xml. That not very elegant. Does anybody know, how I can configure the schema with a property or by manipulation the JDBC connection string? I'm using Oracle 10g, 10_2_3 Patch. Thanks a lot.

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  • Seam/Hibernate and PostgreSQL -- Any issues?

    - by Shadowman
    I'm currently working on a project that makes use of Seam/Hibernate (JPA) on MySQL. I'm reconsidering moving towards PostgreSQL after investigating some of the features that it provides. My question is, is there anything I need to worry about with this configuration? Limitations? Gotchas? Things to watch out for? There will be some BLOBs stored in the database (images, X.509 certificates, etc.) Will that be a problem using PostgreSQL? Are there any particular configuration changes or tweaks that I should make in my Hibernate configuration? Thanks for any advice you can give!

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  • SQLAlchemy Custom Type Which Contains Multiple Columns

    - by Kekoa
    I would like to represent a datatype as a single column in my model, but really the data will be stored in multiple columns in the database. I cannot find any good resources on how to do this in SQLAlchemy. I would like my model to look like this(this is a simplified example using geometry instead of my real problem which is harder to explain): class 3DLine(DeclarativeBase): start_point = Column(my.custom.3DPoint) end_point = Column(my.custom.3DPoint) This way I could assign an object with the (x, y, z) components of the point at once without setting them individually. If I had to separate each component, this could get ugly, especially if each class has several of these composite objects. I would combine the values into one encoded field except that I need to query each value separately at times. I was able to find out how to make custom types using a single column in the documentation. But there's no indication that I can map a single type to multiple columns. I suppose I could accomplish this by using a separate table, and each column would be a foreign key, but in my case I don't think it makes sense to have a one to one mapping for each point to a separate table, and this still does not give the ability to set the related values all at once.

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  • How to map combinations of things to a relational database?

    - by Space_C0wb0y
    I have a table whose records represent certain objects. For the sake of simplicity I am going to assume that the table only has one row, and that is the unique ObjectId. Now I need a way to store combinations of objects from that table. The combinations have to be unique, but can be of arbitrary length. For example, if I have the ObjectIds 1,2,3,4 I want to store the following combinations: {1,2}, {1,3,4}, {2,4}, {1,2,3,4} The ordering is not necessary. My current implementation is to have a table Combinations that maps ObjectIds to CombinationIds. So every combination receives a unique Id: ObjectId | CombinationId ------------------------ 1 | 1 2 | 1 1 | 2 3 | 2 4 | 2 This is the mapping for the first two combinations of the example above. The problem is, that the query for finding the CombinationId of a specific Combination seems to be very complex. The two main usage scenarios for this table will be to iterate over all combinations, and the retrieve a specific combination. The table will be created once and never be updated. I am using SQLite through JDBC. Is there any simpler way or a best practice to implement such a mapping?

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  • Error in creating alias in formula tag

    - by Senthilnathan
    Hi all I have a sql query in formula tag inside property tag. In that query i am creating alias name but the hibernate appends table name and throwing me error. select sum(e.salary) as sal from employee e but hibernate changes to select sum(e.salary) as employee.sal from employee e how to avoid this .... it should recognise as sal inside of employee.sal !!!

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  • How to pass json via a form element

    - by becomingGuru
    I have this swf (flash) file that provides the json that needs to be sent to the server. I wrote a very simple jQuery: function submitForm(swf_json) { $('#swfjson').val(swf_json); #swfjson is an input of type hidden $('#titleForm').submit(); } and the swf will call the submitForm above and I receive the request.POST in django as usual. But, django is interpreting the swf_json as a string "Object object" >>>type(request.POST['swfjson']) <type 'unicode'> Of course I can pass the json as a string to the view function. Doesn't seem good to me. Any other way of passing the json object to the django view?

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  • Getting my webapp to be database agnostic with Hibernate...

    - by JellyHead
    So the ultimate in scope-creep came in the other day: since we're using Hibernate, could we make our webapp run on Oracle as well as MySQL, interchangably? I thought this would be a simple case of changing hibernate.cfg.xml so that instead of explicity stating MySQL-specific options, it would reference a JNDI datasource, allowing the application to build regardless of the database we intend to deploy to. Then changing to a different database would simply mean changing the separate datasource configuration in JBoss, Jetty, WebLogic etc. Is this realistic? Well, I got as far as setting that up in Jetty, but What's tripping me up right now is error about the hibernate.dialect not having been set in hibernate.cfg.xml. But If I set the dialect there, then my app is still going to be built in either MySQL or Oracle flavours, which is not really what I want. Either I'm trying to attempt the impossible or I've missed something fundamentally obvious... anyone else had a similar problem (and subsequent solution/workaround)?

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  • Java JPA @OneToMany neededs to reciprocate @ManyToOne?

    - by bguiz
    Create Table A ( ID varchar(8), Primary Key(ID) ); Create Table B ( ID varchar(8), A_ID varchar(8), Primary Key(ID), Foreign Key(A_ID) References A(ID) ); Given that I have created two tables using the SQL statements above, and I want to create Entity classes for them, for the class B, I have these member attributes: @Id @Column(name = "ID", nullable = false, length = 8) private String id; @JoinColumn(name = "A_ID", referencedColumnName = "ID", nullable = false) @ManyToOne(optional = false) private A AId; In class A, do I need to reciprocate the many-to-one relationship? @Id @Column(name = "ID", nullable = false, length = 8) private String id; @OneToMany(cascade = CascadeType.ALL, mappedBy = "AId") private List<B> BList; //<-- Is this attribute necessary? Is it a necessary or a good idea to have a reciprocal @OneToMany for the @ManyToOne? If I make the design decision to leave out the @OneToMany annotated attribute now, will come back to bite me further down.

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  • Database Structure for CakePHP Models

    - by Michael T. Smith
    We're building a data tracking web app using CakePHP, and I'm having some issues getting the database structure right. We have Companies that haveMany Sites. Sites haveMany DataSamples. Tags haveAndBelongToMany Sites. That is all set up fine. The problem is "ranking" the sites within tags. We need to store it in the database as an archive. I created a Rank model that is setup like this: rank ( id (int), sample_id (int), tag_id (int), site_id (int), rank (int), total_rows) ) So, the question is, how do I create the associations for tag, site and sample to rank? I originally set them as haveMany. But the returned structures don't get me where I'd like to be. It looks like: [Site] => Array ( [Sample] = Array(), [Tag] = Array() ) When I'm really looking for: [Site] => Array ( [Tag] = Array ( [Sample] => Array ( [Rank] => Array ( ...data... ) ) ) ) I think that I may not be structuring the database properly; so if I need to update please let me know. Otherwise, how do I write a find query that gets me where I need to be? Thanks! Thoughts? Need more details? Just ask!

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  • Hibernate pluralization

    - by matiasf
    I have A MySQL database currently in production use for a CakePHP application A Java SE application accessing the same database via Hibernate, currently in development. I'm using the Netbeans "automigrate" feature to create the POJO classes and XML files (do I really need the XML files when using annotations?). As the schema is quite complex creating the tables manually is way too much work. Cake expects all DB tables to be pluralized (the Address class is automagically mapped to the addresses table). When running the Netbeans automigration it then does pluralization on the already pluralized table names (I'm getting Addresses.java and setAddresseses() methods). I know I'm asking for trouble running two very different data layers against the same database, but I'd like to know if it's possible to have Netbeans generating the POJO classes in singular form or if there is another (better) way to manage this.

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  • How to map a property for HQL usage only (in Hibernate)?

    - by ManBugra
    i have a table like this one: id | name | score mapped to a POJO via XML with Hibernate. The score column i only need in oder by - clauses in HQL. The value for the score column is calculated by an algorithm and updated every 24 hours via SQL batch process (JDBC). So i dont wanna pollute my POJO with properties i dont need at runtime. For a single column that may be not a problem, but i have several different score columns. Is there a way to map a property for HQL use only? For example like this: <property name="score" type="double" ignore="true"/> so that i still can do this: from Pojo p order by p.score but my POJO implementation can look like this: public class Pojo { private long id; private String name; // ... } No Setter for score provided or property added to implementation. using the latest Hibernate version for Java.

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  • JPA entitylisteners and @embeddable

    - by seanizer
    I have a class hierarchy of JPA entities that all inherit from a BaseEntity class: @MappedSuperclass @EntityListeners( { ValidatorListener.class }) public abstract class BaseEntity implements Serializable { // other stuff } I want all entities that implement a given interface to be validated automatically on persist and/or update. Here's what I've got. My ValidatorListener: public class ValidatorListener { private enum Type { PERSIST, UPDATE } @PrePersist public void checkPersist(final Object entity) { if (entity instanceof Validateable) { this.check((Validateable) entity, Type.PERSIST); } } @PreUpdate public void checkUpdate(final Object entity) { if (entity instanceof Validateable) { this.check((Validateable) entity, Type.UPDATE); } } private void check(final Validateable entity, final Type persist) { switch (persist) { case PERSIST: if (entity instanceof Persist) { ((Persist) entity).persist(); } if (entity instanceof PersistOrUpdate) { ((PersistOrUpdate) entity).persistOrUpdate(); } break; case UPDATE: if (entity instanceof Update) { ((Update) entity).update(); } if (entity instanceof PersistOrUpdate) { ((PersistOrUpdate) entity).persistOrUpdate(); } break; default: break; } } } and here's my Validateable interface that it checks against (the outer interface is just a marker, the inner contain the methods): public interface Validateable { interface Persist extends Validateable { void persist(); } interface PersistOrUpdate extends Validateable { void persistOrUpdate(); } interface Update extends Validateable { void update(); } } All of this works, however I would like to extend this behavior to Embeddable classes. I know two solutions: call the validation method of the embeddable object manually from the entity validation method: public void persistOrUpdate(){ // validate my own properties first // then manually validate the embeddable property: myEmbeddable.persistOrUpdate(); // this works but I'd like something that I don't have to call manually } use reflection, checking all properties to see if their type is of one of their interface types. This would work, but it's not pretty. Is there a more elegant solution?

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  • Best way to model Customer <--> Address

    - by Jen
    Every Customer has a physical address and an optional mailing address. What is your preferred way to model this? Option 1. Customer has foreign key to Address Customer (id, phys_address_id, mail_address_id) Address (id, street, city, etc.) Option 2. Customer has one-to-many relationship to Address, which contains a field to describe the address type Customer (id) Address (id, customer_id, address_type, street, city, etc.) Option 3. Address information is de-normalized and stored in Customer Customer (id, phys_street, phys_city, etc. mail_street, mail_city, etc.) One of my overriding goals is to simplify the object-relational mappings, so I'm leaning towards the first approach. What are your thoughts?

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  • How to implement automatic reflection of direct SQL Updates of the underlying database, in an ActiveRecord in Ruby on Rails ?

    - by Vadim Eisenberg
    Hello ! I am new to Ruby on Rails and I have a (maybe naive) question: I want to implement reflection of direct SQL Updates of the underlying database in an ActiveRecord (and finally in the generated html). By "direct updates" I mean updating the database bypassing the ActiveRecord methods, for example by MySQL console. I guess here MySQL triggers could be used that would call some stored procedure that would cause the appropriate ActiveRecord to be reloaded. Is there some automatic handling of this scenario in ActiveRecord/Ruby on Rails ? Did somebody implement this scenario ? Can somebody recommend using other MVC frameworks to reflect direct changes in mapped databases ?

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  • Hibernate / MySQL Bulk insert problem

    - by Marty Pitt
    I'm having trouble getting Hibernate to perform a bulk insert on MySQL. I'm using Hibernate 3.3 and MySQL 5.1 At a high level, this is what's happening: @Transactional public Set<Long> doUpdate(Project project, IRepository externalSource) { List<IEntity> entities = externalSource.loadEntites(); buildEntities(entities, project); persistEntities(project); } public void persistEntities(Project project) { projectDAO.update(project); } This results in n log entries (1 for every row) as follows: Hibernate: insert into ProjectEntity (name, parent_id, path, project_id, state, type) values (?, ?, ?, ?, ?, ?) I'd like to see this get batched, so the update is more performant. It's possible that this routine could result in tens-of-thousands of rows generated, and a db trip per row is a killer. Why isn't this getting batched? (It's my understanding that batch inserts are supposed to be default where appropriate by hibernate).

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  • ReflectionTypeLoadException when I try to run Enable-Migrations with Entity Framework 5.0

    - by Eric Anastas
    I'm trying to use Entity Framework for the first time on one of my projects. I'm using the code first workflow to automatically create my database. Intitaly setting up the database worked fine. Now I'm trying to migrate changes in my classes into the database. The tutorial I'm reading says I need to run "Enable-Migrations" in the package manager console. Yet when I do this I get the following error PM> Enable-Migrations System.Reflection.ReflectionTypeLoadException: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information. at System.Reflection.RuntimeModule.GetTypes(RuntimeModule module) at System.Reflection.RuntimeModule.GetTypes() at System.Reflection.Assembly.GetTypes() at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.FindType[TBase](String typeName, Func`2 filter, Func`2 noType, Func`3 multipleTypes, Func`3 noTypeWithName, Func`3 multipleTypesWithName) at System.Data.Entity.Migrations.Design.ToolingFacade.GetContextTypeRunner.RunCore() at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.Run() Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information. What am I doing wrong? How do I retrieve the loader exceptions property? Also NuGet says I have EF 5.0, but Version property of the EntityFramework item in my project references says 4.4.0.0. I'm not sure if this is related.

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