Hi,

I have one many-to-many association table DepartmentToUser with columns:

DepartmentID
UserID
PrimaryCode

Now I want to create the domain object for it and override the hashcode() and equals() method.

What properties should I use for that?

I think I can not use DepartmentID and UserID because they are set by Hibernate when the objects are saved. PrimaryCode alone is not unique. So it can not be used as Business Key.

I think my case is trivia; probably I am missing something since I am new to Hibernate.

Any kind of help will be greatly appreciated.

http://www.hibernate.org/109.html

use whatever makes sense and will remain unchanged for the relative life of the object. But, primary keys generated by dbs aren't bad choices, if that is the only defining unique value.

Hi kochcp,

Thanks for the reply.

I have a query regarding primary keys generated by dbs.

I have read in "Hibernate in Action" that these keys should not be used for hashcode() and equals() implementation.

Lets assume we are using DepartmentID and UserID to generate hashcode(). Now these properties are not set initially. But we add an instance of DepartmentToUser to a HashSet. Now we save the Department and User. So at that time IDs are set by Hibernate. So the hashcode changes for DepartmentToUser when it is contained by the Set. This should not happen.

Let me know your thoughts.

oh, well if you're using a Set, then you have to use something else.