我們如何基於另一個檢視建立 MySQL 檢視?


在 MySQL 中,我們可以基於其他檢視建立一個檢視。要了解這一點,我們有檢視“Info”,其資料如下 -

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)

現在,藉助以下查詢,我們正在建立另一個檢視名稱為“info_less”,它基於現有檢視“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)

更新於:22-6月-2020

332 瀏覽

開啟您的 職業之旅

完成課程並獲得認證

開始學習
廣告