MySQL Get Different Records Bewteen Two Tables

Question

I need to show "Scheduled vs Actual" report which shows difference between the two tables in MySQL database that hold attendance for school.

I have two tables called Booking and Attendance.

Data stored in the tables are as below:

Booking

Id Student   Date     IsAbsent
1  John      20160216    1 //NO
2  Bob       20160217    1 //NO
3  Zara      20160218    1 //NO

Attendance

Id Student    Date     IsAbsent
1  John       20160216    0 //YES
2  Bob        20160217    0 //YES
3  Mary       20160217    1 //NO

Basically I want to show the output as

**Id | Student | Day_1 | Day_2  |  Day_3**
 ==== ========= ======  =======  ======
   1 | John    |ABSENT | NULL   | NULL 
   2 | Bob     |NULL   |ABSENT  | NULL
   3 | Mary    |NULL   |NEW     | NULL
   4 | Zara    |DELETED|NULL    | NULL

ABSENT John in Booking's table is Marked as 1(False) but in Attendance table he is marked as 0(YES) so I want to show as 'ABSENT'

NEW Mary has an entry only in Attendance table but NOT IN Booking table.

DELETED Zara was originally booked and is in Booking table but is not in Attendance table.

I have created SQL Fiddle of schema and the query I am using but it always return nulls.

My SQL Query is like below..

 SELECT * FROM 
((SELECT
  a.Student as student,
   MAX( case
       when a.DropDate='20160216' && a.IsAbsent=0 && s.IsAbsent=1 then 'Absent'
       when (select count(*) from attendance where DropDate='20160216')=0 && (select count(*) from staging where DropDate='20160216')>0 then 'DELETED Booking'
       when (select count(*) from attendance where DropDate='20160216')>0 && (select count(*) from staging where DropDate='20160216')=0 then 'New Booking' 
       else ' ' end ) as 'day_1',
  MAX( case 
       when a.DropDate='20160217' && a.IsAbsent=0 && s.IsAbsent=1 then 'Absent'
       when (select count(*) from attendance where DropDate='20160217')=0 && (select count(*) from staging where DropDate='20160217')>0 then 'DELETED Booking'
       when (select count(*) from attendance where DropDate='20160217')>0 && (select count(*) from staging where DropDate='20160217')=0 then 'New Booking' 
       else ' '  end ) as 'day_2',
  MAX( case 
       when a.DropDate='20160218' && a.IsAbsent=0 && s.IsAbsent=1 then 'Absent'
       when (select count(*) from attendance where DropDate='20160218')=0 && (select count(*) from staging where DropDate='20160218')>0 then 'DELETED Booking'
       when (select count(*) from attendance where DropDate='20160218')>0 && (select count(*) from staging where DropDate='20160218')=0 then 'DELETED Booking' 
       else ' '  end ) as 'day_3'
FROM Attendance a LEFT JOIN Booking s on a.Student=s.Student
WHERE a.DropDate IN ('20160216','20160217','20160218')
   AND  NOT EXISTS 
      ( SELECT 1
        FROM Booking AS p
        WHERE p.Student = a.Student
          AND p.IsAbsent = a.IsAbsent
          AND p.DropDate = a.DropDate
      )
)
UNION 
(SELECT
  t.Student as student,
  MAX( case
       when t.DropDate='20160216' && a.IsAbsent=0 && t.IsAbsent=1 then 'Absent'
       when (select count(*) from attendance where DropDate='20160216')=0 && (select count(*) from staging where DropDate='20160216')>0 then 'DELETED Booking'
       when (select count(*) from attendance where DropDate='20160216')>0 && (select count(*) from staging where DropDate='20160216')=0 then 'New Booking' 
       else ' ' end ) as 'day_1',
  MAX( case 
       when a.DropDate='20160217' && a.IsAbsent=0 && t.IsAbsent=1 then 'Absent'
       when (select count(*) from attendance where DropDate='20160217')=0 && (select count(*) from staging where DropDate='20160217')>0 then 'DELETED Booking'
       when (select count(*) from attendance where DropDate='20160217')>0 && (select count(*) from staging where DropDate='20160217')=0 then 'New Booking' 
       else ' '  end ) as 'day_2',
  MAX( case 
       when a.DropDate='20160218' && a.IsAbsent=0 && t.IsAbsent=1 then 'Absent'
       when (select count(*) from attendance where DropDate='20160218')=0 && (select count(*) from staging where DropDate='20160218')>0 then 'DELETED Booking'
       when (select count(*) from attendance where DropDate='20160218')>0 && (select count(*) from staging where DropDate='20160218')=0 then 'DELETED Booking' 
       else ' '  end ) as 'day_3'
FROM Booking t LEFT JOIN attendance a on t.Student=a.Student
WHERE t.DropDate IN ('20160216','20160217','20160218')
  AND  NOT EXISTS 
      ( SELECT 1
        FROM Attendance AS u
        WHERE u.Student = t.Student
          AND u.IsAbsent = t.IsAbsent
          AND u.DropDate = t.DropDate
      )
)) tbl
ORDER BY  student

Any help would be highly appreciated.

Answer 1

Im' not sure you can output an inline layout within a MySQL query, unless you make a procedure... I don't know if this is ok for you as it has a slightly different layout, but it works :

(select s.Student,
       s.ClassRoom,
       s.DropDate,
       if(s.IsAbsent=1&&a.IsAbsent=0,'ABSENT','PRESENT')
from Staging s inner join Attendance a on a.Student = s.Student and a.ClassRoom = s.ClassRoom and a.DropDate = s.DropDate)
UNION ALL
(Select s.Student,
       s.ClassRoom,
       s.DropDate,
       'DELETED'
from Staging s left join Attendance a on a.Student = s.Student and a.ClassRoom = s.ClassRoom and a.DropDate = s.DropDate
where a.Student is null)
UNION ALL
(Select a.Student,
       a.ClassRoom,
       a.DropDate,
       'NEW'
from Staging s right join Attendance a on a.Student = s.Student and a.ClassRoom = s.ClassRoom and a.DropDate = s.DropDate
where s.Student is null)
order by Student, DropDate;