Perhaps I am missing something obvious, but what is the point of creating two foreign key constraints that would enforce the integrity constraint? =20 Justin Cave <jcave@xxxxxxxxxxx> Distributed Database Consulting, Inc. http://www.ddbcinc.com/askDDBC -----Original Message----- From: askdba-bounce@xxxxxxxxxxxxx [mailto:askdba-bounce@xxxxxxxxxxxxx] On Behalf Of Regis Biassala Sent: Friday, October 01, 2004 8:01 AM To: askdba@xxxxxxxxxxxxx Subject: [askdba] Strange behavior I've tested this against: oracle8i,9i,10g and MSSQL 2000, it is behaving exactly the same... I came across this while debugging an installation scripts... See test below: SQL> create table parent (id int not null primary key); Table created. SQL> create table child(parentid int); Table created. SQL> alter table child add constraint fk_constraint_1 foreign key(parentid) 2 references parent(id); Table altered. SQL> alter table child add constraint fk_constraint_2 foreign key(parentid) 2 references parent(id); alter table child add constraint fk_constraint_2 foreign key(parentid) * ERROR at line 1: ORA-02275: such a referential constraint already exists in the table SQL>=20 SQL>=20 SQL> drop table child; Table dropped. SQL> create table child 2 (parentid int, 3 constraint fk_constraint_1 foreign key(parentid) references parent(id), 4 constraint fk_constraint_2 foreign key(parentid) references parent(id)); Table created. I wanted to share this with you, so be aware of this behavior. ----------------------- Regis Biassala (DBA) Direct: +353 1 8063613