我们如何基于另一个视图创建 MySQL 视图？

在 MySQL 中，我们可以基于其他视图创建一个视图。要了解这一点，我们有视图“Info”，其数据如下 -

mysql> Create view info AS Select Id, Name, Subject FROM student_info;
Query OK, 0 rows affected (0.11 sec)

mysql> Select * from Info;
+------+---------+------------+
| Id | Name | Subject |
+------+---------+------------+
| 101 | YashPal | History |
| 105 | Gaurav | Literature |
| 125 | Raman | Computers |
| NULL | Ram | Computers |
+------+---------+------------+
4 rows in set (0.00 sec)

现在，借助以下查询，我们正在创建另一个视图名称为“info_less”，它基于现有视图“info” -

mysql> Create view info_less AS Select Id, Name, Subject FROM info WHERE id >= 120;
Query OK, 0 rows affected (0.25 sec)

mysql> Select * from info_less;
+------+-------+-----------+
| Id | Name | Subject |
+------+-------+-----------+
| 125 | Raman | Computers |
+------+-------+-----------+
1 row in set (0.03 sec)

George John

更新于:22-6月-2020

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