MySQL日常语句练习——单表DDL_DML_DQL语句练习

前言

数据库名称可以为【schoolDB】，字符集【utf8】，排序规则【utf8_general_ci】。

1.建表语句——DDL

CREATE TABLE `student` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '学号',
  `creatDate` datetime DEFAULT NULL COMMENT '创建时间',
  `userName` varchar(20) DEFAULT NULL COMMENT '用户名',
  `pwd` varchar(36) DEFAULT NULL COMMENT '密码',
  `phone` varchar(11) DEFAULT NULL COMMENT '手机号',
  `age` tinyint(3) DEFAULT NULL COMMENT '年龄',
  `sex` char(2) DEFAULT NULL COMMENT '性别',
  `introduce` varchar(255) DEFAULT NULL COMMENT '简介',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

2.插入语句——DML

insert into student values (0,'2024-03-25 13:57:00','土拨鼠王子','123456','1234567890','18','动物','一只拥有高级灵魂的土拨鼠');
insert into student values (0,'2025-02-08 10:00:00','无名大侠','5678900','098765432','19','动物','可以永远开心吗');
insert into student (userName,introduce)values('呵呵哒','只就是一个烂梗啊大哥');
select*from student

3.基础查询语句——DQL

#1.基础查询
select *from student;
#2.分列匿名以及筛选数据查询
select userName as ;'姓名',age'年龄',sex'性别',introduce'简介'
from student
where pwd is not null;
#3.去重查询
select distinct sex '性别类型'from student;
#4.排序查询
select userName as '姓名',age '年龄'，sex'性别',introduce'简介'from student ORDER BY age desc;
#5.分页查询·limit这是个重载函数，
#1个参数的limit用法是显示多少条信息
select*from student limit 2;
select *from student limit 4,2;