About unique



... ( issue #78 ). Added support of @Column(unique="true") and equivalent ORM XML ( issue #79 ). Fixed ...


Entity Type is not found (error 301) in Query

Overall test OpenJPA, HibernateJAP, EclipseLink and ObjectDB. No Problem with OpenJPA, HibernateJAP, EclipseLink For ObjectDB there is one query in following method, where the full qualified class name is necessary. See method code - red part Otherwise an error will occure. ... "User.checkConstraints(): Property email isn't unique!" ) ; } }   ...


JPA Named Queries

Explains how to define and how to run JPA named queries.... selected carefully to avoid collision (e.g. by using the unique entity name as a prefix). It makes sense to add the above  ...



  During the evaluation of ObjectDB (We're currently developing with EclipseLink/mysql) I noticed was the following: ... Similarly, see this forum thread regarding setting a unique constraint when using ObjectDB. ObjectDB ...


Error during cascaded merge

Hello! I have a new problem with ObjectDB 2.5.5_02. This issue appeared after the upgrade from 2.5.5. I get the following exception: ... = { "unit" , "configDate" } , unique = "true" ) public class ChannelConfigurationSet ...


GROUP BY and HAVING clauses

Explains how to use the GROUP BY and HAVING clauses in a JPA/JPQL query.... The properties that are used for grouping (each group has unique value combination). Aggregate calculations (count, sum, ...


Multiple joins did not return expected result

Hello, I have 3 entity classes: Event - String title Calendar - List<Event> @OneToMany SharedCalendar extends Calendar - Calendar original Now I want to retrieve all events from a specific calendar by its id like: ... The event variable is defined twice. You should use a unique name for every query variable. ObjectDB Support ...


A few questions on object database design

I've been trying to model a database that stores data in an MMORPG. With ObjectDB, a lot of things are easier to perform. Intuitively, I created an entity class called player and stored everything about the player as embeddable classes. However, my colleague questions about this structure, since we would be looking at persisting data from the server every minute or two per player. He has stability issues with the ObjectDB if we are accessing the same table all the time.... After all, everything stored in player instances are unique to that player... So, is it OK to store that much information in ...


How best to unbind all names?

My JDO application does inserts with binds, and then subsequently does bulk deletes using this code: ... field, which may be set as a primary key or as a unique index. This will also solve the orphan problem.   ...



(Optional) Unique constraints that are to be placed on the table.(Annotation Element of javax.persistence.Table)