Re: Adding Ref. Integrity

scthomp_at_ibm.net (Simon Thompson) writes:

>alter table CHILD
> add (constraint CP_NUMBER
> foreign key (C_NUMBER)
> references Parent (P_NUMBER);

Have you tried checking the table using:

   select * from child a where not exists (select 'x' from parent b    where b.p_number = a.c_number)

This should display the problem rows in your child table. (problem child?)

I had a problem like this once that turned out to be caused by trailing blanks in a varchar2 column. The data LOOKED fine, but Oracle didn't like it.

---
Michael Nolan, Sysop for the DBMS RoundTable on GEnie
nolan_at_tssi.com, dbms_at_genie.com, nolan_at_inetnebr.com
(posted from nolan_at_helios.unl.edu)