I was reading one of the papers on the quest website about data modeling. An example was presented and I did not believe the results so I tried it out. Of course the writer ( Phd) was correct.
Does anyone know why does not enforce RI constraint if any of the foreign key colums are NULL. I took it literally that if I insert any record in table_2 that a corresponding record must be in the parent(table_1). Apparently this is not so. Someone please explain. Thanks Rick drop table table_2; drop table table_1; create table table_1 ( a number not null, b number not null, c number, constraint table_1_pk primary key (a,b)); create table table_2 ( a number, b number, d number not null, e number not null, f number, constraint pk_table_2 primary key (d,e), constraint fk_table_2_reference_table_1 foreign key (a,b) references table_1 (a,b)) / insert into table_2 values(1,NULL,3,4,5); 1 row processed. -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
