MySQL学习必备

1.学生表DDL

CREATE TABLE `student` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `createDate` datetime DEFAULT NULL,
  `userName` varchar(20) DEFAULT NULL,
  `pwd` varchar(36) DEFAULT NULL,
  `phone` varchar(11) DEFAULT NULL,
  `age` tinyint(3) DEFAULT NULL,
  `sex` char(2) DEFAULT NULL,
  `inteoduce` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

2.插入学生信息DML

INSERT INTO student VALUES(0,'2024-02-25 10:00:00','赵灵儿','123',
'15612345678',16,'女','逍遥哥哥，你终于找到我了' );
INSERT INTO student VALUES(0,'2024-02-25 10:00:00','王语嫣','123',
'15612345678',17,'女','慕容复，我与你不共戴天' );
INSERT INTO student VALUES(0,'2024-02-25 10:00:00','龙姑娘','123',
'15612345678',22,'女','我想过过过儿过过的日子' );
INSERT INTO student VALUES(0,'2024-02-25 10:00:00','杨过','123',
'15612345678',18,'男','一遇杨过误终身' );
INSERT INTO student VALUES(0,'2024-02-25 10:00:00','杨逍','123',
'15612345678',27,'男','杨过与程英之子' );
INSERT INTO student VALUES(0,'2024-02-25 10:00:00','黄蓉','123',
'15612345678',18,'女','我是黄蓉' );
INSERT INTO student VALUES(0,'2024-02-25 10:00:00','白羊','123',
'15612345678',21,'男','我要开始说谎了' );

实际效果：

3.基础查询测试DQL

# 基础查询
SELECT * FROM `student`；
#筛选列（匿名）与筛选数据行
select userName as 姓名,age'年龄',sex'性别',intouduce'简介'
from student
where pwd is not null;
#分页 limit有两个重载函数常用
#一个参数为显示条数
#一个参数为从那条开始查询（下标从0开始计算），零一参数为显示条数
select * from student limit 3,2;#从4（0-3）开始查询2条。
#排序，order by根据数值类型进行排序会比较准确
select * from student order by age desc limit 3;
#去重语句distinct
select * distinct sex '性别类型' from student;