mysql - SUM(column name) 给我的结果与在 SQL Server 中手动求和列名不同。为什么？

Question

为什么 SUM(Sold) 给我的结果与手动对该字段求和不同？

如果我手动对 Sold 字段求和，这是给我正确的查询:

SELECT     CustCode, FiscalYear, Sold 
FROM         DBNAME.dbo.SALESDETAIL
WHERE     (FiscalYear = YEAR({ fn NOW() }))
and CustCode = '248'
GROUP BY CustCode, FiscalYear, Sold

但是如果我尝试使用 SUM 函数，我会得到错误的金额。谁能帮帮我？

SELECT     CustCode, FiscalYear, SUM(Sold) 
FROM         DBNAME.dbo.SALESDETAIL
WHERE     (FiscalYear = YEAR({ fn NOW() }))
and CustCode = '248'
GROUP BY CustCode, FiscalYear

目标是只返回一个结果——CustCode、FiscalYear 和 Sum(Sold)。感谢任何指点!

Answer 1

SELECT CustCode, FiscalYear, Sold 
FROM DBNAME.dbo.SALESDETAIL
WHERE (FiscalYear = YEAR({ fn NOW() }))
  AND CustCode = '248'
GROUP BY CustCode, FiscalYear, Sold;

与

相同

SELECT  DISTINCT CustCode, FiscalYear, Sold 
FROM DBNAME.dbo.SALESDETAIL
WHERE (FiscalYear = YEAR({ fn NOW() }))
  AND CustCode = '248';

基本上，您摆脱了多个 Sold 值。

尝试求和:

SELECT CustCode, FiscalYear, Sold 
FROM DBNAME.dbo.SALESDETAIL
WHERE (FiscalYear = YEAR({ fn NOW() }))
  AND CustCode = '248';

并与 SUM(Sold) 结果进行比较。