Question

我有一个按ID分组的表，想按日期过滤

StudentTable
DateTime StudentId Grade

SELECT DateTime, StudentId, AVG(Grade)
FROM StudentTable
WHERE CONVERT(DATE, DateTime, 102) BETWEEN CONVERT(DATE, '11-1-2018', 102) 
AND CONVERT(DATE, '12-02-2018', 102)
GROUP BY StudentId

但这给我错误选择列表中的“ DateTime”列无效，因为它不包含在聚合函数或GROUP BY子句中。我该怎么办？谢谢进阶

Answer 1

这解决了我的问题。但是，如果您有更好的解决方案，请告诉我。

SELECT StudentId, AVG (Grade) FROM 
    (SELECT * FROM StudentTable
    WHERE CONVERT(DATE, DateTime, 102) BETWEEN CONVERT(DATE, '11-1-2018', 102) 
    AND CONVERT(DATE, '12-02-2018', 102)
) MainT
GROUP BY MainT.StudentId

Answer 2

只需使用 BETWEEN 子句，而不是将String Date手动转换为Date。

SELECT DateTime, StudentId, AVG(Grade)
FROM StudentTable
WHERE DateTime BETWEEN '11-1-2018' AND '12-02-2018'
GROUP BY StudentId;

从W3Schools检索。

按日期过滤并按条件分组

2 个答案: