為了說明使用 LEFT JOIN 的 MySQL 視圖的制作,我們使用“Customers”和“Resreve”表中的以下數據 –
mysql> Select * from customers; +-------------+----------+ | Customer_Id | Name | +-------------+----------+ | 1 | Rahul | | 2 | Yashpal | | 3 | Gaurav | | 4 | Virender | +-------------+----------+ 4 rows in set (0.00 sec) mysql> Select * from reserve; +------+------------+ | ID | Day | +------+------------+ | 1 | 2017-12-30 | | 2 | 2017-12-28 | | 2 | 2017-12-25 | | 1 | 2017-12-24 | | 3 | 2017-12-26 | +------+------------+ 5 rows in set (0.00 sec)
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現在,以下查詢將使用上述表上的 LEFT JOIN 創建一個名為“customer_VLeft”的視圖,其中包含尚未預訂任何汽車的客戶的姓名。
mysql> Create view customer_Vleft AS SELECT NAME from customers LEFT JOIN RESERVE ON customer_id = id WHERE id IS NULL; Query OK, 0 rows affected (0.13 sec) mysql> Select * from customer_Vleft; +----------+ | NAME | +----------+ | Virender | +----------+ 1 row in set (0.00 sec)
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