Anna Li wrote: > > Hi, > > I created a unique index on a table called REGISTRATION_K, but no unique > constraint. Last week when the application tried to insert a record into > the table, we got following error in the log file: > > Oracle::st execute failed: ORA-00001: unique constraint (REGISTRATION_K) > violated > > However, the record was inserted into the table successfully. There are no > duplicate records in the table. Could anyone explain why? > > Any input will be highly appreciated. Thanks in advance. > > Anna >
Anna, 1) For both historical and implementation reasons, there is a bit of confusion between unique indexes and unique constraint. ORA-00001 (notice the low number ... it has been here since the beginnings) used to be the 'duplicate value in index' error (when constraints were a notion unknown of Oracle). A unique constraint is enforced by a unique index, and by force a unique index creates an implicit unique constraint. 2) You are misinterpreting. The record was NOT inserted successfully. It wasn't inserted at all. What you found in the table was the original row, which caused the redundant insertion fo fail. -- Regards, Stephane Faroult Oriole Software -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Stephane Faroult 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).
