如何通过从基表中选择基于模式匹配的数据来创建 MySQL 视图?
mysqlmysqli database
MySQL LIKE 运算符用于根据模式匹配选择数据。同样,我们可以将 LIKE 运算符与视图结合使用,以从基表中选择基于模式匹配的特定数据。为了理解这个概念,我们使用具有以下数据的基表"student_info" −
mysql> Select * from Student_info; +------+---------+------------+------------+ | id | Name | Address | Subject | +------+---------+------------+------------+ | 101 | YashPal | Amritsar | History | | 105 | Gaurav | Chandigarh | Literature | | 125 | Raman | Shimla | Computers | | 130 | Ram | Jhansi | Computers | | 132 | Shyam | Chandigarh | Economics | | 133 | Mohan | Delhi | Computers | +------+---------+------------+------------+ 6 rows in set (0.00 sec)
示例
以下查询将创建一个名为‘Info’的视图,使用‘LIKE’运算符根据模式匹配选择一些特定值 −
mysql> Create or Replace view Info AS SELECT * from student_info WHERE Name LIKE '%Ra%'; Query OK, 0 rows affected (0.11 sec) mysql> Select * from Info; +------+--------+------------+------------+ | id | Name | Address | Subject | +------+--------+------------+------------+ | 105 | Gaurav | Chandigarh | Literature | | 125 | Raman | Shimla | Computers | | 130 | Ram | Jhansi | Computers | +------+--------+------------+------------+ 3 rows in set (0.00 sec)
我们也可以将 NOT 与 LIKE 运算符一起使用,如下所示 −
mysql> Create or Replace view Info AS SELECT * from student_info WHERE Name NOT LIKE'%Ra%'; Query OK, 0 rows affected (0.14 sec) mysql> Select * from info; +------+---------+------------+-----------+ | id | Name | Address | Subject | +------+---------+------------+-----------+ | 101 | YashPal | Amritsar | History | | 132 | Shyam | Chandigarh | Economics | | 133 | Mohan | Delhi | Computers | +------+---------+------------+-----------+ 3 rows in set (0.00 sec)