如何基于另一个现有视图创建 MySQL 视图?

mysqlmysqli database

在 MySQL 中,我们可以基于另一个现有视图创建视图。为了便于理解,我们拥有包含以下数据的视图"Info" −

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,我们将基于现有视图‘info’创建另一个视图名称‘info_less’,该视图 −

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)

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