python中的mysql数据库LIKE操作符详解 python中的mysql数据库LIKE操作符

LIKE 操作符用于在 WHERE 子句中搜索列中的指定模式。
语法：

SELECT column_name(s)FROM table_nameWHERE column_name LIKE pattern

pattern这里就是放指定模板的地方，而这里就要用到“ % ”，也叫做通配符
【python中的mysql数据库LIKE操作符详解】%如果是放在条件前面，那就是查以...结尾的数据；例如：%李
%如果是放在条件后面，那就是查以...开头的数据；例如：李%
%如果是在条件前后都存在，那就是查包含的数据；例如：%李%
小知识点：

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '%z' at line 1

1064的错误就是LIKE查询时(语法错误)，通配符处没加引号，所以才会报错...
正确展示例如："%李%"
示例1：终端运行sql且WHERE子句中使用LIKE
查询地址以Hang开头的人员信息

root@7c6316b19d80:/# mysql -u root -pEnter password: Welcome to the MySQL monitor.Commands end with ; or \g.Your MySQL connection id is 140Server version: 5.6.51 MySQL Community Server (GPL) mysql> mysql> select * from test_user where address like 'Hang%'; +----+--------+-------------+----------+| id | name| mobile| address|+----+--------+-------------+----------+|3 | python | 18856565858 | Hangzhou ||4 | java| 17756565858 | Hangzhou ||5 | php| 15556565858 | Hangzhou ||6 | c#| 17748484142 | Hangzhou |+----+--------+-------------+----------+4 rows in set (0.00 sec)mysql>

查询地址以u结尾的人员信息

mysql> select * from test_user where address like '%u'; +----+--------+-------------+----------+| id | name| mobile| address|+----+--------+-------------+----------+|3 | python | 18856565858 | Hangzhou ||4 | java| 17756565858 | Hangzhou ||5 | php| 15556565858 | Hangzhou ||6 | c#| 17748484142 | Hangzhou |+----+--------+-------------+----------+4 rows in set (0.00 sec)mysql>

示例2：使用python脚本执行含LIKE的sql语句
查询地址包含z字符的人员信息

import pymysql # 连接数据库connection = pymysql.connect(host="localhost", user="root", password="123456",database="testing", port=3306, charset='utf8',cursorclass=pymysql.cursors.DictCursor) try:with connection:with connection.cursor() as cursor:sql = """SELECT*FROMtest_userWHEREaddress LIKE '%z%'; """cursor.execute(sql)result = cursor.fetchall()for i in result:print(i) except pymysql.err.MySQLError as _error:raise _error

{'id': 3, 'name': 'python', 'mobile': '18856565858', 'address': 'Hangzhou'}{'id': 4, 'name': 'java', 'mobile': '17756565858', 'address': 'Hangzhou'}{'id': 5, 'name': 'php', 'mobile': '15556565858', 'address': 'Hangzhou'}{'id': 6, 'name': 'c#', 'mobile': '17748484142', 'address': 'Hangzhou'} Process finished with exit code 0

查询地址不包含z字符的人员信息

try:with connection:with connection.cursor() as cursor:sql = """SELECT*FROMtest_userWHEREaddress NOT LIKE '%z%'; """cursor.execute(sql)result = cursor.fetchall()for i in result:print(i) except pymysql.err.MySQLError as _error:raise _error

{'id': 1, 'name': '张三三', 'mobile': '17748484141', 'address': '浙江杭州'}{'id': 9, 'name': '111', 'mobile': '18847474549', 'address': '浙江杭州'} Process finished with exit code 0

至此，使用LIKE操作符查询完毕...