日期:2014-05-16  浏览次数:21159 次

mysql 添加字段、删除字段、调整字段顺序

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;