The question is not very clear (at least to me). But the difference between primary key and unique key is that primary key does not allow null values, while unique - does.
Igor Neyman, OCP DBA [EMAIL PROTECTED] -----Original Message----- [EMAIL PROTECTED] Sent: Tuesday, July 08, 2003 3:54 AM To: Multiple recipients of list ORACLE-L hi all I have the following question for you : We have a mainframe database with tables which have composite primary keys with an ascending and a descending item. For example a table with license regisitrations with primary key items LICENSE in ascending and REGISTRATION_DATE in descending order. As far as i know this is not possible with Oracle, only a unique index should be a candidate to do this. I said should be, because if you need a foreign key relation to this specific composite index i get an ORA-2270 !. Anyone with an explanation why a create of a composite unique index with an ascending and descending order works and not with the primary key clause ? Is this triggered in oracle 9i or 10i ? thanks vr.gr. G Kor Sr. System Engineer I&DM Db RDW Holland -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- 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). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Igor Neyman 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).
