duplicate issue?

[phiona]

hello all,
My table stores a serial and the status with ID as the primary key which I set. My problem is like this
ID Serial Status
1 12345 b
2 12345 b
3 12345 b
4 12345 b
5 12345 y

What I want to enable is that any time the combination of serial & status as 'b' can be duplicate and serial and status 'y' cannot be duplicate only one. So, how to enforce this integrity in my database? Please help me guys.
Thankz. -- This message may have been cut off and the rest will only be shown to members. To become a member, click here --

[inder]

Instead of having a table serial_status(id,serial,status), split the table so that you have two tables serial_status_b(id,serial) and serial_status_y(id,serial). If the (id,serial) need to be unique, make a third table referenced by these two by a foreign key constraint.
Hope it will help you. -- This message may have been cut off and the rest will only be shown to members. To become a member, click here --