Question

我需要分组后的行数。

SELECT COUNT(CheckNumber)
FROM myTable
WHERE Status = 'Good'
GROUP BY CheckNumber

结果：

Row 1 = 1
Row 2 = 15
Row 3 = 5

我也尝试过使用DISTINCT

SELECT COUNT(DISTINCT CheckNumber)
FROM myTable
WHERE Status = 'Good'
GROUP BY CheckNumber

结果：

Row 1 = 1
Row 2 = 1
Row 3 = 1

我希望结果为3

Answer 1

在我看来，GROUP BY根据你想要的内容完全是多余的。为什么不呢：

SELECT COUNT(distinct CheckNumber) 
FROM myTable
WHERE Status = 'Good'

Answer 2

如果我理解正确，你可以这样做：

SELECT COUNT(*) FROM
(
   SELECT COUNT(CheckNumber)
   FROM myTable
   WHERE Status = 'Good'
   GROUP BY CheckNumber
) as myData

根据要求，这应该给你总共3个。