my dog learned polymorphism*
The moose likes EJB Certification (SCBCD/OCPJBCD) and the fly likes difference between joinColumn and PrimaryKeyJoinColumni Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login

Win a copy of Android Security Essentials Live Lessons this week in the Android forum!
JavaRanch » Java Forums » Certification » EJB Certification (SCBCD/OCPJBCD)
Bookmark "difference between joinColumn and PrimaryKeyJoinColumni" Watch "difference between joinColumn and PrimaryKeyJoinColumni" New topic

difference between joinColumn and PrimaryKeyJoinColumni

Senthil Kumar
Ranch Hand

Joined: Mar 13, 2006
Posts: 264
i have seen these two annotations used when we want to relate two entities.
what i want to know is how one differs from the other..

when you really want something, all the universe always conspires in your favour.<br /> <br />SCJP1.5-77%<br />SCWCD-89%
Rodrigo W Bonatto
Ranch Hand

Joined: Aug 20, 2004
Posts: 62

You can use joinColumn to define a join column in the table that references the primary key of the associated table.
PrimaryKeyJoinColumn is a little diferent and much easier when the primary key of the related entities are identical, so you do not need to specify a join column.


Shivani Chandna
Ranch Hand

Joined: Sep 18, 2004
Posts: 380
Usage of PrimaryKeyJoinColumn:

(1) For defining linkage to a secondary table:

When no additional foreign key column in either table.In this case, @PrimaryKeyJoinColumn is used instead of an @JoinColumn annotation.

Usage of JoinColumn:

A relationship mapping where one table has a reference to another table.
i.e existence of foreign key column. In JPA its called join columns and
@JoinColumn annotation is the primary annotation used to configure these types of columns. Eg:

/** Code speaks louder than words */
I agree. Here's the link:
subject: difference between joinColumn and PrimaryKeyJoinColumni
Similar Threads
Is Math class IMMUTABLE?
Comparing Two Files
session handling in jsp
Listeners not configured in DD
How to run two class files in two different JVM?