對多個表使用CREATE VIEW

Question

我正在嘗試使用CREATE VIEW以及3個不同表中的多個單元格，並在兩個單元格之間進行乘法運算。 某處存在語法錯誤，但我似乎無法識別它。

CREATE VIEW ORDERS AS CustFirstname, CustLastName, o.Ordernumber AS OrderNumber, 
o. OrderDate AS OrderDate, o.ShipDate AS ShipDate, c.QuotedPrice, 
c.QuantityOrdered, c.QuotedPrice * c.QuantityOrdered AS ItemTotal FROM Customers 
NATURAL JOIN Orders o NATURAL JOIN Order_Details c

我嘗試獲取的輸出是| CustFirstname | CustLastName | OrderNumber | OrderDate | ShipDate | ItemTotal |。

更新：如果我用“選擇”替換“創建視圖訂單為”，它似乎可以工作

Answer 1

您缺少最重要的語句“ SELECT”。

CREATE VIEW ORDERS AS 
SELECT CustFirstname, CustLastName, o.Ordernumber AS OrderNumber, 
o. OrderDate AS OrderDate, o.ShipDate AS ShipDate, c.QuotedPrice, 
c.QuantityOrdered, c.QuotedPrice * c.QuantityOrdered AS ItemTotal FROM Customers 
NATURAL JOIN Orders o NATURAL JOIN Order_Details c

Answer 2

在CREATE VIEW語句上，您缺少查詢的SELECT ：

CREATE VIEW ORDERS AS 
    SELECT CustFirstname, CustLastName, o.Ordernumber AS OrderNumber, 
        o. OrderDate AS OrderDate, o.ShipDate AS ShipDate, c.QuotedPrice, 
        c.QuantityOrdered, c.QuotedPrice * c.QuantityOrdered AS ItemTotal 
    FROM Customers NATURAL JOIN Orders o NATURAL JOIN Order_Details c

在CREATE VIEW的定義上，您可以看到select_statement是必需的：

CREATE
    [OR REPLACE]
    [ALGORITHM = {UNDEFINED | MERGE | TEMPTABLE}]
    [DEFINER = { user | CURRENT_USER }]
    [SQL SECURITY { DEFINER | INVOKER }]
    VIEW view_name [(column_list)]
    AS select_statement
    [WITH [CASCADED | LOCAL] CHECK OPTION]

您可以在官方文檔中找到有關CREATE VIEW更多信息。