Hi,

I have an entity class that has a String collection. I want that collection to be ordered, so I used the @OrderBy annotation (from JPA).
The problem is that the annotation seems to be ignored, no matter what value I give to the annotation (even invalid ones):

• @OrderBy
• @OrderBy("ASC")
• @OrderBy("DESC")
• @OrderBy("some invalid order by clause")

Here is the entity class:



Here is the DDL for the collection table:



When an entity is fetched, the following SQL is ran:


Hibernate: select documentty0_.id as id2_, documentty0_.name as name2_ from document_types documentty0_ where documentty0_.id=?
Hibernate: select allowedatt0_.document_type_id as document1_2_0_, allowedatt0_.extension as extension0_ from allowed_attachment_types allowedatt0_ where allowedatt0_.document_type_id=?


As you can see, the SELECT for retrieving the allowedAttachmentTypes does not have an ORDER BY clause.

I could use a SortedSet or whatever, but I should still be able to use the annotation.

The JPA JavaDocs say:


Is this a bug or am I doing something wrong?

Hibernate version: 3.5.6
Database: MySQL

Hi,

I think you're confusing OrderBy with the OrderColumn annotation. The latter is for storing an order attribute in the database,
OrderBy is for sorting "in-memory" so you won't see anything special in the select statement.
But the ordering should take effect in the collection (maybe try a list first) after the select, did you actually check the ordering of the elements?

regards,

Robin.

I'm not talking about the @OrderColumn annotation (that is used for specifying the column that keeps the index of a list for ordering purposes).
I'm not talking about the Hibernate's @Sort annotation either (that is used for in-memory collection sorting).

I am trying to use the @OrderBy, that should add an ORDER BY clause when fetching a collection.
I am using the @OrderBy for a one-to-many relationship backed collection and it works as it should. But it seems to be ignored on my basic type collection mapping.

Ok, forget my comment that "you won't see anything special in the select statement", that's plain stupid. (I thought that a JPA implementation
is free to either use order by in the select statement or sort in memory but the more I think about it ... as I said - stupid!)

But I'm not sure what to expect in your case: you have a primary key (document_type_id, extension) and you're using
a collection of a basic type (String). See the following javadoc of @OrderBy:
"If the ordering element is not specified for an entity association, ordering by the primary key of the associated entity is assumed."
...
"When OrderBy is applied to an element collection of basic type, the ordering will be by value of the basic objects and the property or field name is not used. "

The word "assumed" leaves some room for interpretation but I also would expect an "order by extension" in your case, so maybe it's really a bug.
With Hibernate 3.6 I can confirm that the following does work and yields a "select .. order by position:


where VocalistPicture is an embedabble:


Hope that helps!

Robin.

Try using