一、数据定义语句(DDL)
数据库操作
●登录数据库:
bash
mysql -uroot -proot
●创建数据库:
bash
create database test
●查看所有数据库:
bash
show databases
●选择数据库并使用:
bash
use test
●查看所有数据表:
bash
show tables
●删除数据库:
bash
drop database test
表操作
●创建表:
bash
create table emp(ename varchar(10),hiredate date,sal decimal(10,2),deptno int(2))
create table dept(deptno int(2),deptname varchar(10))
●查看表的定义:
bash
desc emp
●查看表定义(详细):
bash
show create table emp \G
●删除表:
bash
drop table emp
●修改表字段:
bash
alter table emp modify ename varchar(20)
●添加表字段:
bash
alter table emp add column age int(3)
●删除表字段:
bash
alter table emp drop column age
●字段改名;
bash
alter table emp change age age1 int(4)
●修改表名:
bash
alter table emp rename emp1
二、数据操纵语句(DML)
插入记录
●指定名称插入:
bash
insert into emp (ename,hiredate,sal,deptno) values ('zhangsan','2018-01-01','2000',1)
●不指定名称插入:
bash
insert into emp values ('lisi','2018-01-01','2000',1)
●批量插入数据:
bash
insert into dept values(1,'dept1'),(2,'dept2')
修改记录
bash
update emp set sal='4000',deptno=2 where ename='zhangsan'
删除记录
bash
delete from emp where ename='zhangsan'
查询记录
●查询所有记录:
bash
select * from emp
●查询不重复的记录:
bash
select distinct deptno from emp
●条件查询:
bash
select * from emp where deptno=1 and sal<3000
●排序和限制:
bash
select * from emp order by deptno desc limit 2
●分页查询(查询从第0条记录开始10条):
bash
select * from emp order by deptno desc limit 0,10
●聚合(查询部门人数大于等于1的部门编号):
bash
select deptno,count(deptno) from emp group by deptno having count(deptno) >= 1
●连接查询:
bash
select * from emp e left join dept d on e.deptno=d.deptno
●子查询:
bash
select * from emp where deptno in (select deptno from dept)
●记录联合:
bash
select deptno from emp union select deptno from dept
数据控制语句(DCL)
权限相关
●授予操作权限 (将test数据库中所有表的select和insert权限授予test用户):
bash
grant select,insert on test.* to 'test'@'localhost' identified by '123'
●查看账号权限:
bash
show grants for 'test'@'localhost'
●收回操作权限:
bash
revoke insert on test.* from 'test'@'localhost'
●授予所有数据库的所有权限:
bash
grant all privileges on *.* to 'test'@'localhost'
●授予所有数据库的所有权限(包括grant):
bash
grant all privileges on *.* to 'test'@'localhost' with grant option
●授予SUPER、PROCESS、FILE权限(系统权限不能指定数据库):
bash
grant super,process,file on *.* to 'test'@'localhost'
●只授予登录权限:
bash
grant usage on *.* to 'test'@'localhost'
●刷新权限并立即生效:
bash
flush privileges
帐号相关
●删除账号:
bash
drop user 'test'@'localhost'
●修改自己的密码:
bash
set password = password('123')
●管理员修改他人密码:
bash
set password for 'test'@'localhost' = password('123')
其他
字符集相关
●查看字符集:
bash
show variables like 'character%'
●创建数据库时指定字符集:
bash
create database test2 character set utf8
时区相关
●查看当前时区(UTC为世界统一时间,中国为UTC+8):
bash
show variables like "%time_zone%"
●修改mysql全局时区为北京时间,即我们所在的东8区:
bash
set global time_zone = '+8:00';
●修改当前会话时区:
bash
set time_zone = '+8:00'