Question

我使用了CASE函数来创建新列。当我尝试使用新列时，出现以下列错误：

没有这样的列：price_each

SELECT  o1.orderid,
        productid,
        shipcountry,
        quantity,
        unitprice,
        discount,
        case
            WHEN discount > 0
                THEN unitprice - (unitprice * discount)
            ELSE unitprice
        END AS price_each,
        quantity * price_each AS ttl
    FROM orders o1 JOIN OrderDetails o2
        ON o1.orderid = o2.orderid

Answer 1

请检查以下内容：

SELECT  o1.orderid,
        productid,
        shipcountry,
        quantity,
        unitprice,
        discount,
        case
            WHEN discount > 0
                THEN unitprice - (unitprice * discount)
            ELSE unitprice
        END AS price_each,
        quantity * (SELECT price_each) AS ttl
    FROM orders o1 JOIN OrderDetails o2
        ON o1.orderid = o2.orderid

或者可以通过以下方式完成：

SELECT ord_id,productid,shipcountry,quantity,unitprice,discount,price_each, (price_each * quantity) AS ttl FROM 
(SELECT  o1.orderid AS ord_id,
        productid,
        shipcountry,
        quantity,
        unitprice,
        discount,
        case
            WHEN discount > 0
                THEN unitprice - (unitprice * discount)
            ELSE unitprice
        END AS price_each
    FROM orders o1 JOIN OrderDetails o2
        ON o1.orderid = o2.orderid)
AS VR_table

SQLite中的列错误

1 个答案: