Help - Funny Constraint

Hi All,

I want to enforce the following.

Table C1 has two fields F1, F2

I want to prevent the update of field F1 if the value of F2 exists in another table C2.

So if

C1.F1       C1.F2
1           11
2           12

and

C2.FF

11

then the value 1 in C1 shou1d not be updatable but the value 2 should be (as there is no value of 12 in C2).

I can use a trigger but how can I stop the update from happenning based on a value the trigger works out ?

Altenatively can I somehow use a CHECK_CONSTRAINT ?

Thanks v. much

Kevin. Received on Fri Aug 28 1998 - 05:41:13 CDT