mysql 增加修改字段类型及删除字段类型，mysql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)

alter table `user_movement_log` drop column Gatewayid

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：

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;