MySQL 表常用操作命令

• 修改字段

alter table w_user modify column `pwd` varchar(32) COLLATE utf8mb4_bin NOT NULL;

• 修改字段名

alter table w_user change column `pwd` `newPwd` varchar(32) COLLATE utf8mb4_bin NOT NULL;

• 添加字段

alter table w_user add column `salt` varchar(10) COLLATE utf8mb4_bin NOT NULL after `pwd`;

• 查询数据库占用空间等信息

use information_schema;
select * from TABLES where TABLE_NAME='w_message';

• 修改表名

alter table w_user rename to w_user_new;

• 查看表信息

SELECT TABLE_SCHEMA,TABLE_NAME,TABLE_ROWS,DATA_LENGTH/1024/1024,CREATE_TIME,UPDATE_TIME FROM information_schema.tables where TABLE_SCHEMA='wuiFarmsDemo' order by UPDATE_TIME DESC;