I am having a situation in which I need some help...

As you can tell from the subject of this post - I am a bit confused.

As you read my issue, let me forewarn you that I am still fairly a beginner with the hibernate framework.


Let me describe the scenario.

First the entities in my system...
I have a Developer, a ProgramLanguage and a Framework...(hope this doesn't confuse matters).

Ok, so how do these entities relate?

Well I figure a ProgramLanguage can be supported by one or more Frameworks.

A Framework can support One or more ProgramLanguages.

Example: Hibernate supports java and .net. Java is supported by Hibernate and Spring

This is my first many-to-many relationship. So if I go back in time to Database Modeling 101, this will tell me that I will have to set up an association table.

Ok, so now lets introduce the associations for developers. Lets say we want to capture all the Frameworks/Language combos a developer likes to use. Therefore, we say...

A developer likes to use one or more Frameworks/Language.
A Framework/Language is used by one or more developers.

Another many to many...

Ok, now let me create the tables...just paraphrasing here...

CREATE TABLE Developer(ID, NAME);
CREATE TABLE ProgramLanguage(ID, NAME);
CREATE TABLE Framework(ID, NAME);

Now the association tables...
CREATE TABLE ProgramLanguage_Framework(ID, ProgramLanguageId, FrameworkId)

CREATE TABLE DEVELOPER_PROGRAMLANGUAGE_FRAMEWORK(ID, ProgramLanguageFrameworkId, DeveloperId)

Here is a sample dataset...
Developer
ID | NAME
1 | Roy
2 | Gavin

ProgramLanguage
ID | NAME
1 | Java
2 | .Net

Framework
ID | NAME
1 | Hibernate
2 | Spring

ProgramLanguage_Framework
ID | ProgramLanguageId, FramworkId
1 | 1 (Java) | 1 (Hibernate)
2 | 2 (Java) | 2 (Spring)
3 | 3 (.Net) | 1 (Hibernate)

DEVELOPER_PROGRAMLANGUAGE_FRAMEWORK
ID | ProgramLanguageFrameworkId | DeveloperId
1 | 1 (Java and Hibernate) | 1 (Roy)
2 | 1 (Java and Hibernate) | 2 (Gavin)
3 | 2 (Java and Spring) | 1 (Roy)
4 | 3 (.Net and Hibernate) | 2 (Gavin)

So this is how I understood to Map these relationships in hibernate...



When Hibernate starts...
I get the following exception upon mapping...


I am 100% sure that [FrameworkId,ProgramLanguageId] is not the primary key of ProgramLanguageFramework.

Need help with Hibernate? Read this first:
http://www.hibernate.org/ForumMailingli ... AskForHelp

Hibernate version:
3.0

Mapping documents:

Code between sessionFactory.openSession() and session.close():
N/A
Full stack trace of any exception that occurs:

Name and version of the database you are using:
MySql 5.x
The generated SQL (show_sql=true):

Debug level Hibernate log excerpt:


Problems with Session and transaction handling?

Read this: http://hibernate.org/42.html

[/code]

does anyone have an idea why this might be happening...The primary key is definitely not what hibernate thinks it is...

All I want is to be able to find out which frameworks/Languages a Developer likes...

I remember at one point I did have a composite key definied. I had the two columns hibernate is looking created as UNIQUE in mysql...Is it possible that Hibernate is holding on to some sort of cached version of that mapping definition. I am going crazy on this one...The mappings all seem correct, but i am still getting that exception. I just don't get it...