网站制作是那个盲盒小程序搭建

目录

条件查询

1）准备一张表

2）插入数据

3）条件查询格式

1---比较运算符 >大于

2---比较运算符 < 小于

3---比较运算符 >= 大于等于

4---比较运算符 <= 小于等于

5---比较运算符 != 不等于

6---比较运算符 <> 不等于

7---比较运算符 between ...and .. 某一区间 

8---比较运算符 in(集合) 某个集合

9-- 前缀查询

10-- 后缀查询

11-- 包括查询

逻辑运算符

1--逻辑运算符 And 

2--逻辑运算符 &&

3--逻辑运算符 ||

4--逻辑运算符 or

5--逻辑运算符 Not

---

条件查询

1）准备一张表

CREATE table role(roleid INT PRIMARY KEY AUTO_INCREMENT,rolename VARCHAR(200),roleskill VARCHAR(300),rolesex CHAR(1),rolemonkey int,roleinfo VARCHAR(200),rolehealth INT
);

2）插入数据

INSERT into role VALUES
(null, '小玖', '暗影', '女', 500000, '猎手', 50000),
(null, '暗色', 'coc', '男', 60000, '骑士', 50000),
(null, '黎明', '曙光', '女', 70000, '战士', 50000),
(null, '雪夜', '银色', '男', 30000, '猎人', 50000),
(null, '张久', '酒心', '女', 50000, '肉盾', 50000),
(null, '雪色', '雪风', '男', 50000, '女魔', 50000),
(null, '安久', '蛋定', '女', 50000, '魔法士', 50000);

3）条件查询格式

select 列名 from 表明 where 条件表达式

1---比较运算符 >大于

查找角色金钱大于 70000

select * from role WHERE rolemonkey > 70000 ;

2---比较运算符 < 小于

查找角色金钱小于50000

select * from role WHERE rolemonkey < 50000 ;

3---比较运算符 >= 大于等于

查找角色金钱大于等于60000

select * from role WHERE rolemonkey >= 60000 ;

4---比较运算符 <= 小于等于

查找角色金钱小于等于60000

select * from role WHERE rolemonkey <= 60000 ;

5---比较运算符 != 不等于

查找角色金钱不等于50000

select * from role WHERE rolemonkey != 50000 ;

6---比较运算符 <> 不等于

select * from role WHERE rolemonkey <> 60000 ;

7---比较运算符 between ...and .. 某一区间 

查找金钱区间为 50000 到 70000

select * from role WHERE rolemonkey BETWEEN 50000 and 70000;

8---比较运算符 in(集合) 某个集合

查找金钱为30000和60000

SELECT * from role where rolemonkey in(30000,60000);

9-- 前缀查询

select * from role where rolename like '雪%';

10-- 后缀查询

select * from role where roleinfo like '%士';

11-- 包括查询

SELECT * from role where  roleinfo LIKE '%法%';

逻辑运算符

1--逻辑运算符 And 

SELECT * from role where rolename = '张久' and  rolemonkey = 50000;

2--逻辑运算符 &&

SELECT * from role where rolename = '雪色' &&  rolemonkey = 50000;

3--逻辑运算符 ||

select * from role where roleskill = '银色' || roleskill = 'coc';

4--逻辑运算符 or

select * from role where roleinfo = '猎手' or roleinfo = '女魔';

5--逻辑运算符 Not

select * from role where not(roleinfo = '猎手' or roleinfo = '女魔');