尝试以下查询作为您的报告记录源:
SELECT TestTable.GroupByCol, TestTable.DetailColA
FROM TestTable
WHERE TestTable.DetailColA IN
(SELECT TOP 2 DetailColA FROM TestTable AS TT
WHERE TT.GroupByCol=TestTable.GroupByCol
ORDER BY TT.DetailColA)
ORDER BY TestTable.GroupByCol, TestTable.DetailColA
有关详细信息,请参阅 Allen Browne 的子查询基础知识。
编辑:正如您在评论中提到的,这也可以写成如下:
SELECT a.GroupByCol, a.DetailColA, COUNT(*) As RankNumber
FROM TestTable AS a INNER JOIN TestTable AS b
ON a.GroupByCol = b.GroupByCol
AND a.DetailColA >= b.DetailColA
GROUP BY a.GroupByCol, a.DetailColA
HAVING COUNT(*)<=2
ORDER BY a.GroupByCol, a.DetailColA, COUNT(*)
您必须进行基准测试才能确定,但第二个版本可能更有效。哪个更具可读性可能是个人喜好问题(我发现第一个版本更直观和可读)。