查看

查看变量 show variables like 'auto%';
信息输出： echo "select user,host,password from mysql.user" |mysql -uroot -plingxiangxiang
查看库 show databases;
查看都有哪些库 show databases;
查看某个库的表 use db; show tables \G;
查看表的字段 desc tb;
查看建表语句 show create table tb;
当前是哪个用户 select user();
当前库 select database();
查看数据库版本 select version();
查看mysql状态 show status;
查看mysql队列 show processlist;
查询 select count() from mysql.user; select from mysql.db; select * from mysql.db where host like '10.0.%';
查看权限 show grants for root@'localhost';

select from sutdent where group by stdname a, c where a.id = c.组id group by 字段：字段进行分组
select from information_schema.processlist where info is not null;
查看表索引 show index from 表名

增加

创建库 create database db1;
创建表 create table t1 (id int, name char(40) adress varchar(30));
创建普通用户并授权 grant all on . to databases1.user1 identified by '123456';
grant all on db1. to 'user2'@'10.0.2.100' identified by '111222';
grant all on db1. to 'user3'@'%' identified by '231222';insert into tb1 (id,name) values(1,'aming');
插入 update db1.t1 set name='aaa' where id=1;
创建索引 create index 库名_表名_列名1_列名2 （列名1， 列名2）

删除

删除表 drop table db1.t1; 删除表数据，表结构
删除数据库 drop database db1;
delete from table where 条件判断 删除行数据
char(10) 'aaa '定长，给10个字符，只写了3个，其他7个用空格占用
varchar(10) 'aaa' '变长'

修改

修改mysql参数 show variables like 'max_connect%'; set global max_connect_errors = 1000;
更改密码 UPDATE mysql.user SET password=PASSWORD("newpwd") WHERE user='username' ;
清空表 truncate table db1.t1; 只删除表数据，不删除表结构
修复表 repair table tb1 [use frm];

授权超级用户（对所有库所有表有权限，还可以给其他用户设置权限）：
grant all privileges on . to 'tangnanbing'@'%' identified by '1qaz@WSX' with grant option;