[jboss-user] [EJB 3.0] - Re: Using a JoinTable, getting unique constraint violtions
SmokingAPipe
do-not-reply at jboss.com
Wed Feb 14 17:27:32 EST 2007
I figured out the problem, but not the solution.
Here's the problem:
I have a uni-directional Collection in my Invoice:
@Entity class Invoice {
|
| @OneToMany Collection<Product> getProducts();
|
| }
This results in creating a join table, with a unique constraint on the product_id column, which doesn't work because the Collection can have the same Product multiple times.
The naive solution would be a table that looks like:
invoice_id product_id
| 33 88
| 33 88
But that's not a proper relation. Rows (tuples) must be unique.
What is needed is a third column, which is a row ID. I can't see anything in the docs about how I could do that. Any suggestions?
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