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  • MySql的基本操作

    1. 查询数据:select * from xxx;

      例子:

      (1)select id,username,password from t_user;

      (2)select id,username,password,gender from t_user where gender = '男';

      (3)select id,username,password,gender from t_user where gender is null;

    2.  

      添加数据:insert xxx(id, username) values(xx, "xxx");

      例子:

      insert into t_user(id, username) values(10, "hehehe");

      insert into t_user(id, gender, username, age, password) values(15, '男', 'shihu', 18, '123456');

      insert into t_user values(16, 'benladeng', '123456', '拉登', 'nan', 18);

    3.  

      修改数据:update tablename set xx=xx,xxx=xx where xxx=xxx and xxx=xxx;

    4.  

      删除数据:delete from tablename where xx=xxx and xxx = xxx or xxx = xxx;

    5.  

      DQL数据查询语言

      连接查询

         左外连接

            select

       e.name ename,

       e.gender,

       d.name dname

            from

       t_employee e left outer join t_department d

       on

       e.depart_id = d.id

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  • 原文地址:https://www.cnblogs.com/itjunjun/p/7853841.html
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