mysql第一节

创建数据库

CREATE DATABASE company charset=utf8;

使用

use company;

创建表

create table emp(
eid int primary key,#primary key 设置eid字段为主键
ename varchar(20),
esex varchar(5),
joindate DATE
) charset=utf8;

向emp表中添加数据

insert into emp(eid,ename,esex,joindate) value(1,'张三','男','2019-07-08');
insert into emp(eid,ename,esex,joindate) value(2,'李四','男','2019-07-09');
insert into emp(eid,ename,esex,joindate) value(3,'王五','女','2019-07-10');
insert into emp(eid,ename,esex,joindate) value(4,'赵六','男','2019-07-11');

查询emp表中的数据

select eid,ename,esex,joindate from emp;
select * from emp;

把eid=3的记录，ename的值改为王冰莹

update emp set ename='王冰莹' where eid=3;

删除eid=4的记录

delete from emp where eid=4;

更改表结构

把表名emp改为empioy

alter table emp rename employ;
select * from employ;

把esex字段名改为egender

alter table employ change esex egender varchar(5);
alter table employ add etel varchar(17);