Jpa composite key nullable columns

Question

Hi,

I'm using Hibernate's JPA impl to model some tables. I'm having trouble mapping a table that:

• Has no primary key
• Has a unique index on 4 columns, 3 of which can be nullable

I tried to hack it and define the index as a composite Id, but since some columns are nullable this is not working properly. Is this possible with JPA/Hibernate?

Thanks

Answer 1

It seems that the column that is not nullable should be your primary key. No parts of a composite key should ever be nullable.

You will need to take the nullable properties and place them outside of your primary/composite key.

Also, this looks like a duplicate of http://stackoverflow.com/questions/70909/hibernate-mapping-a-composite-key-with-null-values which came up as #3 when I googled "null composite key".