SQL LIKE 子句 | 弟弟快看-教程

SQL中的 LIKE 子句用于在 WHERE 子句中搜索列中的指定模式

SELECT column_name(s) FROM table_name WHERE column_name LIKE pattern;

pattern 是一个合法的模式字符串，有很多种模式，但最常用的也是最容易记住的就是百分号 ( % ) 可以代替任意字符

演示数据

先在 MySQL 数据库运行下面的语句创建测试数据

CREATE DATABASE IF NOT EXISTS ddkk default character set utf8mb4 collate utf8mb4_unicode_ci;

USE ddkk;

DROP TABLE IF EXISTS lession;

CREATE TABLE lession (
    id int(11) NOT NULL PRIMARY KEY AUTO_INCREMENT,
    name varchar(32) default '',
    views int(11) NOT NULL default '0',
    created_at DATETIME
);

INSERT INTO lession(id,name,views,created_at) VALUES
(1, 'Python DDKK.COM 弟弟快看',981,'2017-04-18 13:52:03'),
(2, 'Scala DDKK.COM 弟弟快看',73,'2017-04-18 16:03:32'),
(3, 'Ruby DDKK.COM 弟弟快看',199,'2017-05-01 06:16:14'),
(4, 'SQL DDKK.COM 弟弟快看', 533,'2017-05-02 08:13:42');

使用SELECT * FROM lession; 运行结果如下

mysql> select * from lession;
+----+---------------------+-------+---------------------+
| id | name                | views | created_at          |
+----+---------------------+-------+---------------------+
|  1 | Python DDKK.COM 弟弟快看     |   981 | 2017-04-18 13:52:03 |
|  2 | Scala DDKK.COM 弟弟快看      |    73 | 2017-04-18 16:03:32 |
|  3 | Ruby DDKK.COM 弟弟快看       |   199 | 2017-05-01 06:16:14 |
|  4 | SQL DDKK.COM 弟弟快看        |   533 | 2017-05-02 08:13:42 |
+----+---------------------+-------+---------------------+

总共有4 条记录

SQL LIKE 操作符

1、如果我们不使用任何通配符，那么LIKE的效果相当于=操作符；

下面的 SQL 语句选取 name 为 Python DDKK.COM 弟弟快看的课程

SELECT * FROM lession WHERE name LIKE 'Python DDKK.COM 弟弟快看';

输出结果如下

mysql> SELECT * FROM lession WHERE name LIKE 'Python DDKK.COM 弟弟快看';
+----+---------------------+-------+---------------------+
| id | name                | views | created_at          |
+----+---------------------+-------+---------------------+
|  1 | Python DDKK.COM 弟弟快看     |   981 | 2017-04-18 13:52:03 |
+----+---------------------+-------+---------------------+

2、因为百分号(%)可以代替任何任意数量的字符，所以下面的SQL语句选取name以S开头的课程；

SELECT * FROM lession WHERE name LIKE 'S%';

运行结果如下

mysql> SELECT * FROM lession WHERE name LIKE 'S%';
+----+--------------------+-------+---------------------+
| id | name               | views | created_at          |
+----+--------------------+-------+---------------------+
|  2 | Scala DDKK.COM 弟弟快看     |    73 | 2017-04-18 16:03:32 |
|  4 | SQL DDKK.COM 弟弟快看       |   533 | 2017-05-02 08:13:42 |
+----+--------------------+-------+---------------------+

3、下面的SQL语句选取name以字符串程序员编程资料站结尾的所有课程；

SELECT * FROM lession WHERE name LIKE '%教程';

输出结果如下

mysql> SELECT * FROM lession WHERE name LIKE '%教程';
+----+---------------------+-------+---------------------+
| id | name                | views | created_at          |
+----+---------------------+-------+---------------------+
|  1 | Python DDKK.COM 弟弟快看     |   981 | 2017-04-18 13:52:03 |
|  2 | Scala DDKK.COM 弟弟快看      |    73 | 2017-04-18 16:03:32 |
|  3 | Ruby DDKK.COM 弟弟快看       |   199 | 2017-05-01 06:16:14 |
|  4 | SQL DDKK.COM 弟弟快看        |   533 | 2017-05-02 08:13:42 |
+----+---------------------+-------+---------------------+

4、下面的SQL语句选取name包含y字母的课程；

SELECT * FROM lession WHERE name LIKE '%y%';

输出结果如下

mysql> SELECT * FROM lession WHERE name LIKE '%y%';
+----+---------------------+-------+---------------------+
| id | name                | views | created_at          |
+----+---------------------+-------+---------------------+
|  1 | Python DDKK.COM 弟弟快看     |   981 | 2017-04-18 13:52:03 |
|  3 | Ruby DDKK.COM 弟弟快看       |   199 | 2017-05-01 06:16:14 |
+----+---------------------+-------+---------------------+

5、通过使用NOT关键字，我们可以选取不匹配模式的记录；

下面的 SQL 语句选取 name 不包含 "y" 的所有课程

SELECT * FROM lession WHERE name NOT LIKE '%y%';

运行结果如下

mysql> SELECT * FROM lession WHERE name NOT LIKE '%y%';
+----+--------------------+-------+---------------------+
| id | name               | views | created_at          |
+----+--------------------+-------+---------------------+
|  2 | Scala DDKK.COM 弟弟快看     |    73 | 2017-04-18 16:03:32 |
|  4 | SQL DDKK.COM 弟弟快看       |   533 | 2017-05-02 08:13:42 |
+----+--------------------+-------+---------------------+

16、SQL LIKE 子句

演示数据

SQL LIKE 操作符