sql - 带有嵌套 group by 子句的 SQL Select 语句

Question

我有 2 张桌子。我需要从 Invoices 中选择列名和一个名为 balance_due 的计算字段。

查询的结果应该是姓名和他们所有记录的余额。

谢谢你的帮助。

Answer 1

SELECT v.vendor_name, i.totalbalance
FROM Vendors as v
     INNER JOIN (
           SELECT vendor_id, sum(invoice_total-payment_total) as totalbalance
           FROM invoices
           GROUP BY vendor_id
     ) as i on i.vendor_id = v.vendor_id

Answer 2

或者还有另一种语法：

;With i As
(
   SELECT vendor_id, sum(invoice_total-payment_total) as totalbalance
   FROM invoices
   WHERE payment_total is not null
   GROUP BY vendor_id
)
SELECT Vendors.vendor_name, i.totalbalance
From Vendors LEFT JOIN i ON Vendors.vendor_id = i.vendor_id