Hello,

I try to incorporate into Hibernate since several weeks, and i hardly got it. But there's a important silly thing that i don't understand:

I defined three tables: task, parameter and task_parameter, which represents the relationship between task and parameter.

(task) 1 ----- n (task_parameter) n ------ 1 (parameter)

So far, so good.

But now i need to save an additional property for every relation of tasks and parameters. In the database design i solved this common issue with an additional column in task_parameter.
But how can i map this with Hibernate?

Thanks for every thought!

Greetings,

Simon

If I understand you correctly, you only have two classes in Java up to now.

In order to specify additional information on the relationship, you have to create a third class representing the relationship and therefore the table task_parameter.
Then you simply convert your many-to-many mapping to two one-to-many mappings (and perhaps the corresponding many-to-one-mappings in the new class).

Heinz,

thanks for your reply. I expected the solution you posted, but i thought there is a way to represent the relation without an additional class that will clutter my clean design ;o)...

Anyway - thanks!

Simon

Alternatively, you can use the approach described here:
http://www.hibernate.org/118.html#A11

"I have a many-to-many association between two tables, but the association table has some extra columns (apart from the foreign keys). What kind of mapping should I use?"