查询是否仅获取在一个日期内具有多个会话的实体?

我不明白为什么需要任何聚合。您只需在同一天为同一员工寻找另一个班次:

SELECT s.*
FROM Shift s 
WHERE s.Date >= @startDate AND
      s.Date <= @endDate AND
      s.ShiftType IN ('TypeA', 'TypeB') AND
      EXISTS (SELECT 1
              FROM Shift s2
              WHERE s2.EmployeeId = s.EmployeeId AND
                    s2.Date = s.Date AND
                    s2.ShiftType IN ('TypeA', 'TypeB') AND
                    s2.ShiftId <> s.ShiftId
             );

请注意,这不包括 employee

您可以使用“WHERE EXISTS”进行如下查询:

SELECT e.EmployeeID
   ,s.ShiftID
   ,s.ShiftDate
   ,s.ShiftType
FROM Employee e
JOIN Shift s ON s.EmployeeId = e.EmployeeId 
    AND (s.Date >= @startDate AND s.Date <= @endDate)
WHERE EXISTS (
    SELECT 1
    FROM Shift s2
    WHERE s2.EmployeeId = s.EmployeeId 
        AND s2.Date = s.Date
    GROUP BY s2.EmployeeId, s2.Date
    HAVING COUNT(*) > 1
)

SELECT 
    s.EmployeeId, s.Date, COUNT(*)
FROM Shift s
GROUP BY s.EmployeeId, s.Date
HAVING COUNT(*) > 1