mysql

增（insert into）

首先创建一个表

CREATE TABLE customers ( userid int NOT NULL AUTO_INCREMENT, name char(50) NOT NULL, address char(200) NOT NULL, email char(50) NOT NULL, PRIMARY KEY(userid) );

插入完整行

INSERT INTO customers values(10010,'小小','北京市朝阳区','1234567@qq.com')

查询已插入的数据

SELECT * FROM customers;

根据列插入数据

INSERT INTO customers(userid,name,adress,email) values('10077','张三','北京市通州区','1234789@qq.com')

多行插入

INSERT INTO customers(userid,name,adress,email) values ('10011','王五','北京市通州区','1234789@qq.com'), ('10012','王五','北京市通州区','1234789@qq.com'), ('10013','王五','北京市通州区','1234789@qq.com');

将一个表里的数据插入到另一个表中

insert into 表 (列名,列名...) select 列名,列名... from 表

删除数据

DELETE FROM customers WHERE userid = 10010;

• 从表中删除所有行
  delete from 表

改

UPDATE customers SET email='123@sina.com' where userid=10011;

检测单个列

SELECT 列名 FROM 表名;

检测多个列

SELECT 列名,列名,列名,列名,... FROM 表名;

检测所有列

SELECT * FROM 表名;

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=等于

select name from customers where name='王五';

<>不等于

select name from customers where name<>'王五';

!=不等于

select name from customers where name!='王五';

<小于

select name from customers where name<'王五';
select * from customers where userid<10013;

<=小于等于

select * from customers where userid<=10013;

>大于

select * from customers where userid>10013;

>=大于等于

select * from customers where userid>=10014;

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通配符

%表示任何字符出现任意次数

SELECT name FROM students WHERE name like “王%”

通配符可在搜索模式中任意位置使用，并且可以使用多个通配符

SELECT name FROM customers WHERE name LIKE '%子%';

另一个有用的通配符是下划线（ ）。下划线的用途与%一样，但下划线只匹配单个字符而不是多个字符
SELECT name FROM customers WHERE name LIKE "李%"; SELECT name FROM customers WHERE name LIKE "王";