在查询的where子句中转换datetime

SELECT *
FROM tblClassAppointments
INNER JOIN tblClassGroups ON tblClassAppointments.GroupID = tblClassGroups.GroupID
WHERE (
        ('2015-07-13' >= StartTime)
        AND ('2015-07-13' <= EndTime)
        AND ('2015-07-13' > StartTime)
        AND ('2015-07-13' >= EndTime)
        )
    OR (
        ('2015-07-13' >= StartTime)
        AND ('2015-07-13' < EndTime)
        AND ('2015-07-13' > StartTime)
        AND ('2015-07-13' <= EndTime)
        )
    OR (
        ('2015-07-13' <= StartTime)
        AND ('2015-07-13' < EndTime)
        AND ('2015-07-13' >= StartTime)
        AND ('2015-07-13' <= EndTime)
        )
    OR (
        ('2015-07-13' <= StartTime)
        AND ('2015-07-13' >= EndTime)
        )
SELECT *
FROM tblClassAppointments
INNER JOIN t