试图将查询放在 phpMyAdmin 中的另一个查询中

Question

我正在尝试将一个查询用作另一个查询的数据源，但我不断收到来自 SELECT 的解析错误。我对 SQL 和 phpmyadmin 还很陌生，不知道为什么会发生这个错误。这是我正在尝试执行的查询：

SELECT  CUS_CODE, 
 COUNT(LINE.INV_NUMBER) AS "Number of Invoices", 
 AVG("Invoice Total") AS "Average Invoice Amount", 
 MAX("Invoice Total") AS "Max Invoice Amount", 
 MIN("Invoice Total") AS "Min Invoice Amount", 
 Sum("Invoice Total") AS "Total Customer Purchases"
FROM    (SELECT CUS_CODE, LINE.INV_NUMBER AS INV_NUMBER,
        Sum(LINE.LINE_UNITS*LINE.LINE_PRICE) AS "Invoice Total"
        FROM    INVOICE, LINE 
        WHERE   INVOICE.INV_NUMBER = LINE.INV_NUMBER
        GROUP BY    CUS_CODE, LINE.INV_NUMBER)
GROUP BY    CUS_CODE;

对不起，如果我的问题不清楚，但我可以回答任何问题以帮助解决问题。

Answer 1

您的查询：

SELECT CUS_CODE,
    COUNT(LINE.INV_NUMBER) AS "Number of Invoices",
    AVG("Invoice Total") AS "Average Invoice Amount",
    MAX("Invoice Total") AS "Max Invoice Amount",
    MIN("Invoice Total") AS "Min Invoice Amount",
    Sum("Invoice Total") AS "Total Customer Purchases"
FROM (
    SELECT CUS_CODE,
        LINE.INV_NUMBER,
        Sum(LINE.LINE_UNITS * LINE.LINE_PRICE) AS "Invoice Total"
    FROM INVOICE,
        LINE
    WHERE INVOICE.INV_NUMBER = LINE.INV_NUMBER
    GROUP BY CUS_CODE, INV_NUMBER
    )
GROUP BY CUS_CODE;

这里有几个问题：

1. 在您的外部查询中，您引用了LINE.INV_NUMBER，但LINE 表在此上下文中不可用。这是您想要的子查询的INV_NUMBER。
2. 您的子查询缺少别名，因此您无法在外部查询中引用它。这只会抛出一个没有别名的错误。

固定：

SELECT t1.CUS_CODE,
    COUNT(t1.INV_NUMBER) AS "Number of Invoices",
    AVG(t1."Invoice Total") AS "Average Invoice Amount",
    MAX(t1."Invoice Total") AS "Max Invoice Amount",
    MIN(t1."Invoice Total") AS "Min Invoice Amount",
    Sum(t1."Invoice Total") AS "Total Customer Purchases"
FROM (
    SELECT CUS_CODE,
        LINE.INV_NUMBER AS INV_NUMBER,
        Sum(LINE.LINE_UNITS * LINE.LINE_PRICE) AS "Invoice Total"
    FROM INVOICE,
        LINE
    WHERE INVOICE.INV_NUMBER = LINE.INV_NUMBER
    GROUP BY CUS_CODE,
        LINE.INV_NUMBER
    ) as t1
GROUP BY CUS_CODE;