我们如何通过从基表中选择一定范围的值来创建MySQL视图？
众所周知，MySQLBETWEEN运算符可用于从某些值范围中选择值。我们可以将BETWEEN运算符与视图一起使用，以从基表中选择一些值范围。为了理解这个概念，我们使用具有以下数据的基本表“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，以使用“BETWEEN”运算符选择特定范围内的某些值-
mysql> Create or Replace view Info AS SELECT * from student_info WHERE Name BETWEEN 'C' AND 'P'; mysql> Select * from info; +------+--------+------------+------------+ | id | Name | Address | Subject | +------+--------+------------+------------+ | 105 | Gaurav | Chandigarh | Literature | | 133 | Mohan | Delhi | Computers | +------+--------+------------+------------+ 2 rows in set (0.00 sec)
类似地，我们可以将NOT与BETWEEN运算符一起使用，以选择与在查询中编写的值不同的值范围-
mysql> Create or Replace view Info AS SELECT * from student_info WHERE Name NOT BETWEEN 'C' AND 'P'; mysql> Select * from Info; +------+---------+------------+-----------+ | id | Name | Address | Subject | +------+---------+------------+-----------+ | 101 | YashPal | Amritsar | History | | 125 | Raman | Shimla | Computers | | 130 | Ram | Jhansi | Computers | | 132 | Shyam | Chandigarh | Economics | +------+---------+------------+-----------+ 4 rows in set (0.00 sec)