Hi,

In my RDBMS, I have table A, B & C.

A has many B and C has many B. It's a many to many relationship with a intermediate table B storing only the primary key of both A and C.

So, when defining my entity classes, should I just define A & C only with @ManyToMany annotations
OR
should I define entity class A, B & C and annotated using @OneToMany from A to B and C to B, then define a @ManyToOne from B to A and B to C.

Please advise.

Hi,
yes you could use the @ManyToMany annotation;
The possible drawbacks are 2:
1)As a design point of you, there is no more an entity representing B.
2)If later on you would need to add more data to B you will have to create the intermediate entity B.

The positive side is of course that if "B" is not an entity but you just used it as intermediate table, hiding it from the code you get much cleaner java classes; also it's easy to implement.

So it all depends if B represents something to you, other than a mere relationship.

Noted on your advice. I think I'll keep an entity to represent B.