1、下载安装mysql
https://dev.mysql.com/downloads/mysql/
选择最新版安装。执行安装过程中需要输入root用户名和密码，自己用你开心
2、下载安装mysql workbench
https://dev.mysql.com/downloads/workbench
3、打开workbench 连接到mysql服务
…

show databases;

建表users/blogs

tables — > create tables —> 完毕之后点击apply

基本sql语句
select username, nickname from users;
select * from blogs order by id desc;
select username, nickname from users where username=’zhangsan’ and password=’1234’;
insert into users (username, password, nickname) values (‘zhangsan’, ‘123’, ‘张三’);
update blogs set content=’内容1内容1’ where id=’1’;
delete from blogs where id=2;
增删改查
查询总数，分页

总数 select count(id) as count from blogs;
分页 select from blogs order by id desc limit 2 offset 2; （offset 2n）

外键

创建外键
Foreign keys
更新限制&删除级联
连表查询
select from blogs inner join users on users.id = blogs.userid;
解决有多个id
select blogs.,users.username,users.nickname from blogs inner join users on users.id = blogs.userid;
ER图