Help with mapping with composite-key

joel_makinen · **Joined:** Mon Mar 06, 2006 9:41 am **Posts:** 3

Hi all, I need some help mapping with composite-keys. I have two tables:

student

Code:

studentid VARCHAR(7)<PK>
age INTEGER
education VARCHAR(5)
faculty VARCHAR(5)
...other fields

studentexam

Code:

studentid VARCHAR(7)<PK>
languageid CHAR(3)<PK>
eventid INTEGER
starttime DATETIME
endtime DATETIME
result FLOAT

I need to map these two tables so that there is a way to find students with an eventid. I am stuck so any good ideas are welcome!!! Thanks in advance!!!

batmat · **Posted:** Wed Jun 28, 2006 4:49 pm

Composite id are never a good idea with Hibernate. It's recommended to define a technical id.

Is your schema a legacy one ? I mean : is it new or already existing and used since a long time ?

If new, you should define an id in studentexam. It would be the primary key. Then define the student_id as an ref to student_id in the student table.

joel_makinen · **Joined:** Mon Mar 06, 2006 9:41 am **Posts:** 3

Schema is new so I will change it to use technical id and use the studentid as a ref. I don't know why I was trying to do this the hard way. Thanks!!!