Hi; mysql> insert into categories (Category, Parent) values ('test', NULL); ERROR 1062 (23000): Duplicate entry '0' for key 1 mysql> describe categories; +----------+-----------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +----------+-----------------+------+-----+---------+-------+ | ID | int(3) unsigned | NO | PRI | NULL | | | Category | varchar(40) | YES | | NULL | | | Parent | varchar(40) | YES | | NULL | | +----------+-----------------+------+-----+---------+-------+ 3 rows in set (0.00 sec)
Why the error? TIA, Victor