Query for Constraints

Hi

I have Table with Two columns

1)SID
2)Owner

First Time No check on insertion:

user has entered record:
SID owner
1 avi


Next time User inserts with same SID must have owner as avi.
means:

SID owner
1 avi is right entry( This entry can be multiple)

1 Julian is wrong entry


is there any check or constraint in oracle for these types of checks

pls. Suggest
rgds.

Avi kumar

You need to write trigger for such kind of requirement... which will check if the new entry is already in the table.. If not then raised an exception ...

I feel you need to work on your table structure.. Why don't you refer to Parent/Child (Foreign key) relationship. Where before inserting a child recond, you need to insert a record into Parent table which will be then refered into Child table.. having a possibility of multiple child records with same Parent Id.

Sameer