SQL query to identify Class Attendance (CAT) records for a section that does not have a corresponding Course Attendance (CAR) record.


SELECT STU.ID, STU.SC, STU.SN, CAT.DT, CAT.SE, CAT.AC, CAR.* 
FROM STU 
    INNER JOIN (SELECT * FROM CAT WHERE DEL = 0) CAT ON STU.SC = CAT.SCL AND STU.ID = CAT.ID 
        LEFT JOIN (SELECT * FROM CAR WHERE DEL = 0) CAR ON STU.SC = CAR.SC AND STU.SN = CAR.SN AND CAT.SE = CAR.SE AND CAT.DT <= CAR.DE AND CAT.DT >= CAR.DS
WHERE STU.DEL = 0 
AND CAR.DEL IS NULL