1. 启动 mysql
    2. docker container start mysql1 
    3. 或者
    4. docker run --name mysql1 -e MYSQL_ROOT_PASSWORD=123456 -p 3306:3306 -d mysql:5.7.28
    5. 进入 mysql
    6. docker exec -it mysql1 bash
    7. mysql -u root -p
    8. 输入密码 123456
    11. 创建数据库
    12. CREATE DATABASE db1 CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
    13. show databases;
    14. use db1;
    15. 创建表
    16. create table users(id serial, name text);
    17. create table staffs(id serial, name text);
    18. create table orders(id serial, user_id bigint unsigned, staff_id bigint unsigned, amount int unsigned);
    20. 创建记录
    21. insert into users (name) values ('XiaoMing');
    22. insert into staffs (name) values ('XiaoHong');
    23. insert into orders(user_id,staff_id, amount) values (1,1, 100);
    24. 使用 inner join
    25. select users.name as uname, orders.amount as amount from users inner join orders on users.id =orders.user_id;
    26. 得到 XiaoMing 100
    28. //T1{[INNER]|{LEFT|RIGHT|FULL}{OUTER}}JOIN T2 ON blloean_expression
    30. //使用事务 一个语句失败 则都不生效
    31. start transaction;
    32. 语句1;  语句2; 语句3;
    33. commit;