78 lines
3.0 KiB
Markdown
78 lines
3.0 KiB
Markdown
# Mysql常用命令
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## 数据定义语句(DDL)
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### 数据库操作
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- 登录数据库：mysql -uroot -proot
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- 创建数据库：create database test
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- 查看所有数据库：show databases
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- 使用数据库：use test
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- 查看所有数据表：show tables
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- 删除数据库：drop database test
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### 表操作
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- 创建表：create table emp(ename varchar(10),hiredate date,sal decimal(10,2),deptno int(2))
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create table dept(deptno int(2),deptname varchar(10))
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- 查看表的定义：desc emp
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- 查看表定义（详细）：show create table emp \G
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- 删除表：drop table emp
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- 修改表字段：alter table emp modify ename varchar(20)
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- 添加表字段：alter table emp add column age int(3)
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- 删除表字段：alter table emp drop column age
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- 字段改名；alter table emp change age age1 int(4)
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- 修改表名：alter table emp rename emp1
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## 数据操纵语句(DML)
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### 插入记录
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- 指定名称插入：insert into emp (ename,hiredate,sal,deptno) values ('zhangsan','2018-01-01','2000',1)
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- 不指定名称插入：insert into emp values ('lisi','2018-01-01','2000',1)
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- 批量插入数据：insert into dept values(1,'dept1'),(2,'dept2')
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### 修改记录
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update emp set sal='4000',deptno=2 where ename='zhangsan'
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### 删除记录
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delete from emp where ename='zhangsan'
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### 查询记录
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- 查询所有记录：select * from emp
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- 查询不重复的记录：select distinct deptno from emp
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- 条件查询：select * from emp where deptno=1 and sal<3000
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- 排序和限制：select * from emp order by deptno desc limit 2
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- 聚合(查询部门人数大于1的部门编号)：select deptno,count(1) from emp group by deptno having count(1) > 1
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- 连接查询：select * from emp e left join dept d on e.deptno=d.deptno
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- 子查询：select * from emp where deptno in (select deptno from dept)
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- 记录联合：select deptno from emp union select deptno from dept
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## 数据控制语句(DCL)
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- 授予操作权限：grant select,insert on test.* to 'test'@'localhost' identified by '123'
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- 收回操作权限：revoke insert on test.* from 'test'@'localhost'
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## 其他
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### 字符集相关
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- 查看字符集：show variables like 'character%'
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- 创建数据库时指定字符集：create database mall character set utf8
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### 修改时区
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- 修改mysql全局时区为北京时间，即我们所在的东8区：set global time_zone = '+8:00';
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- 修改当前会话时区：set time_zone = '+8:00'
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- 立即生效：flush privileges
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### 权限相关
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- 授予所有数据库的所有权限：grant all privileges on *.* to z1@localhost identified by '123'
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- 授予所有数据库的所有权限(包括grant)：grant all privileges on *.* to z1@localhost with grant option
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- 授予SUPER PROCESS FILE权限：grant super,process,file on *.* to z3@localhost
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- 只授予登录权限：grant usage on *.* to z4@localhost
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- 查看账号权限：show grants for z1@localhost
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- 修改自己的密码：set password = password('123')
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- 管理员修改他人密码：set password for 'z1'@'localhost' = password('123')
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- 删除账号：drop user z2@localhost |