That is correct. Use NOT NULL in the definition to force unique keys. [EMAIL PROTECTED] wrote:
>>Description: >> > If a null column is used in a unique index then mysql fails to throw a > key violation when multiple identical inserts (with nulls) are > performed. > >>How-To-Repeat: >> > create table test (a int null, b int null); > alter table test add unique index index_ab (a,b); > insert into test (a,b) values(1,null); > insert into test (a,b) values(1,null); > insert into test (a,b) values(1,null); > select * from test; > +------+------+ > | a | b | > +------+------+ > | 1 | NULL | > | 1 | NULL | > | 1 | NULL | > +------+------+ > 3 rows in set (0.00 sec) > > insert into test (a,b) values(1,1); > insert into test (a,b) values(1,1); > ERROR 1062: Duplicate entry '1-1' for key 1 > >>Fix: >> > No fix. > >>Submitter-Id: <submitter ID> >>Originator: Jon Barker >>Organization: >> > > >>MySQL support: none >>Synopsis: NULLs don't work correctly in unique indexes. >>Severity: serious >>Priority: >>Category: mysql >>Class: >>Release: mysql-3.23.41 (Official MySQL RPM) >> > >>Environment: >> > > --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
