File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
The moose likes Object Relational Mapping and the fly likes Hibernate Query Question Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login

Win a copy of REST with Spring (video course) this week in the Spring forum!
JavaRanch » Java Forums » Databases » Object Relational Mapping
Bookmark "Hibernate Query Question" Watch "Hibernate Query Question" New topic

Hibernate Query Question

Mirrell Knabe
Ranch Hand

Joined: Oct 13, 2008
Posts: 32
Hi, I am relatively new to using hibernate...Is it possible to invoke a query returning multiple rows WITH THE SAME PRIMARY KEY into a list object?....I have tried many things, but keep getting an error that multiple rows are being returned with the same identifier...but, that is what I need returned...Any help or suggestions would greatly be appreciated!
Ankit Garg

Joined: Aug 03, 2008
Posts: 9452

That means that the column in the database that you've marked as primary key in your hibernate mapping is not actually a primary key or is your query such that redundant rows are generated??

SCJP 6 | SCWCD 5 | Javaranch SCJP FAQ | SCWCD Links
Mirrell Knabe
Ranch Hand

Joined: Oct 13, 2008
Posts: 32
Hi query is such that redundant primary keys are generated(returned)...that is what I want...the other row data is unique...for example..

Primary Key Sample Row Field
000001 000001
000001 000002
000001 000003

Is it not possible to return multiple rows with non-unique primary keys?
R George

Joined: Aug 10, 2009
Posts: 5
I dont think it really make sense when you say multiple rows are returned with same primary key. In relational database, a primay key is meant for uniquely identifying a row/record. In case one key is not able to identify a record uniquely, a combination of keys are used(composite key).

And ideally each table should have a primary/composite key in a relational DB.
Paul Sturrock

Joined: Apr 14, 2004
Posts: 10336

Indeed. "non-unique primary key" is an oxymoron. Have a search through this forum for questions about data modelled without a proper primary key. This sort of question gets asked a lot and the pros and cons of doing this have been discussed many times before.

JavaRanch FAQ HowToAskQuestionsOnJavaRanch
Sachin Kumar

Joined: Aug 31, 2008
Posts: 20
I have seen the scenario when it happens after a join query. But I never get exception. Have you checked your mapping your case looks to be of one-to-many mapping and also tru putting logical equal and hashcode method.
I agree. Here's the link:
subject: Hibernate Query Question
It's not a secret anymore!