常用的通过mysql命令来更改表结构的一些sql语句,包括添加、删除、修改字段、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;修改表的存储类型:
ALTER TABLE `table_name` ENGINE = MyISAM;