SQL查找多个值困难

我正在尝试为项目生成正确的SQL

以下是一个示例数据集：

DateTime          |  EmpID |  Function  |  Location
--------------------------------------------------
1/23/2015 2:00PM  |  123   |  1         |  1
1/23/2015 2:10PM  |  123   |  2         |  1
1/23/2015 2:20PM  |  123   |  1         |  2
1/23/2015 2:40PM  |  123   |  2         |  2
1/24/2015 2:00PM  |  321   |  1         |  2
1/24/2015 2:15PM  |  321   |  2         |  2
1/24/2015 2:30PM  |  321   |  1         |  3

我需要对functionid=1且location必须同时等于1和2的所有记录进行计数。因此，将返回第一行和第三行，并将其视为计数1

---

希望我能理解这一点。基本上，我需要知道一名员工在两个地点工作了多少次。任何帮助都将不胜感激。

按EmpId分组并计算位置

SELECT *
  FROM MyTable T1 
 WHERE Function = 1 AND
       NOT EXISTS (SELECT 1 
                     FROM MyTable T2 
                    WHERE T1.EmpId = T2.EmpId AND
                          T1.Function = T2.Function AND
                          T2.Location NOT IN (1, 2))
GROUP BY EmpId
HAVING Count(DISTINCT Location) > 1

但如果您想知道该员工是否在任何两个地点，那么jarlh给出了正确的评论

group by EmpID
having count(distinct location) >= 2

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我还没有测试过，但我认为这会起作用

SELECT EmpID, COUNT(EmpID) AS NumOfTimes
From [Table Name] 
WHERE FunctionID = 1 AND (Location = 1 OR Location = 2)
GROUP BY EmpID 
HAVING NumOfTimes = 2

---

按计数分组（不同位置）>=2如果位置计数为3，这被认为是有效的，但OP只需要1和2，而不是3，如果员工只在位置1呆过几次，而且从未在位置2，则此操作将不起作用。而此代码片段可以解决此问题，确实有助于提高您的帖子质量。请记住，您将在将来回答读者的问题，这些人可能不知道您的代码建议的原因。

SELECT A.EmpID, COUNT(*) 
FROM YOURTABLENAME A 
INNER JOIN YOURTABLENAME B 
ON A.EmpID= B.EmpID
WHERE  A.Location = 1 and B.Location = 2 
and A.Function = B.Function and A.Function = 1
GROUP BY A.EmpID

SELECT EmpID, COUNT(EmpID) AS NumOfTimes
From [Table Name] 
WHERE FunctionID = 1 AND (Location = 1 OR Location = 2)
GROUP BY EmpID 
HAVING NumOfTimes = 2