页次: 1
可以 主键是不能有重复的值的。主键有唯一性
示例
mysql> create table tb_002 ( name char(20) not null primary key ); Query OK, 0 rows affected (0.06 sec) mysql> insert into tb_002 (name) values("www_ipbbs_net"); Query OK, 1 row affected (0.05 sec) mysql> insert into tb_002 (name) values("www_ipbbs_net"); ERROR 1062 (23000): Duplicate entry 'www_ipbbs_net' for key 'PRIMARY' mysql> mysql> desc tb_002; +-------+----------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+----------+------+-----+---------+-------+ | name | char(20) | NO | PRI | NULL | | +-------+----------+------+-----+---------+-------+ 1 row in set (0.00 sec)
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页次: 1