mysql> describe test1; +-------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+-------------+------+-----+---------+-------+ | id | int(11) | YES | | NULL | | | data | varchar(40) | YES | | NULL | | +-------+-------------+------+-----+---------+-------+ 2 rows in set (0.00 sec) mysql> select * from test1; +------+-------+ | id | data | +------+-------+ | 1 | yes | | 1 | no | | 1 | myabe | | 2 | yes | | 1 | yes | +------+-------+ 5 rows in set (0.00 sec) mysql> select distinct * from test1; +------+-------+ | id | data | +------+-------+ | 1 | yes | | 1 | no | | 1 | myabe | | 2 | yes | +------+-------+ 4 rows in set (0.00 sec)