Rumah > Artikel > pangkalan data > mysql 增加修改字段类型及删除字段类型
MySQL添加字段: alter table `user_movement_log` Add column GatewayId int not null default 0 AFTER `Regionid` (在哪个字段后面添加) 删除字段: alter table `user_movement_log` drop column Gatewayid 调整字段顺序: ALTER TABLE `user_movement_lo
MySQL添加字段:
alter table `user_movement_log` Add column GatewayId int not null default 0 AFTER `Regionid` (在哪个字段后面添加)
删除字段:
alter table `user_movement_log` drop column Gatewayid
调整字段顺序:
ALTER TABLE `user_movement_log` CHANGE `GatewayId` `GatewayId` int not null default 0 AFTER RegionID //主键 alter table tabelname add new_field_id int(5) unsigned default 0 not null auto_increment ,add primary key (new_field_id);//增加一个新列 alter table t2 add d timestamp; alter table infos add ex tinyint not null default '0';//删除列 alter table t2 drop column c;//重命名列 alter table t1 change a b integer; //改变列的类型 alter table t1 change b b bigint not null; alter table infos change list list tinyint not null default '0'; //重命名表 alter table t1 rename t2;加索引 mysql> alter table tablename change depno depno int(5) not null; mysql> alter table tablename add index 索引名 (字段名1[,字段名2 …]); mysql> alter table tablename add index emp_name (name);加主关键字的索引 mysql> alter table tablename add primary key(id);加唯一限制条件的索引 mysql> alter table tablename add unique emp_name2(cardnumber);删除某个索引 mysql>alter table tablename drop index emp_name;修改表:
增加字段:
mysql> ALTER TABLE table_name ADD field_name field_type;修改原字段名称及类型: mysql> ALTER TABLE table_name CHANGE old_field_name new_field_name field_type;删除字段: mysql> ALTER TABLE table_name DROP field_name;