Hibernate foreign key

[Cheenath Ajay]

Dear All,

I am not strong in Database concepts,

I am having two tables,
User and Salary

In User table UserID is my primary key and in Salary table UserID and Salary_Date are composite keys. How can i set UserId as foreign key in Salary table? Can i use cascade on delete through Salry mapping file?

Please help me out if it is possible or please let me know where i did wrong?

Thanks in Advance,

Cheenath.

[Michael Duffy]

Originally posted by Cheenath Ajay:
Dear All,

I am not strong in Database concepts,

I am having two tables,
User and Salary

In User table UserID is my primary key and in Salary table UserID and Salary_Date are composite keys. How can i set UserId as foreign key in Salary table? Can i use cascade on delete through Salry mapping file?

Please help me out if it is possible or please let me know where i did wrong?

Thanks in Advance,

Cheenath.

My preference would be for Salary to have a non-composite key. Don't include SALARY_DATE as part of the key.

USER_ID can be foreign key in SALARY:

FOREIGN KEY(USER_ID) REFERENCES (USER) ON DELETE CASCADE ON UPDATE CASCADE

[Cheenath Ajay]

Thanks for the reply!!

but my situation is like sal_datae and userID should be composite key and i cant avoid that by making it as primary key, is there any way like that?

Hope you can help me to find a solution.

Thanks again

Cheenath

[Cheenath Ajay]

Leave the matter of Salary table, just imagine Group table where a User will be having only one group and a Group can have more than one User

USERID+GroupID so it should be a composite key in Group table, am i righ


Please help me out!!

Cheenath

[Emanuel Kadziela]

Forget composite keys altogether, use surrogate keys (like oids) instead of natural keys (like actual meaningful data columns), and use a combination of not null and unique constraints to get the data integrity right. Then, you will have no problem with referential stuff, because you simply reference a surrogate key from one table in another.