Question

There is attendance table like:

| ATID | STID | ATDATE    | PRESENT |
..........................................................
| 1    |  25  | 6/8/2012  | true    |
| 2    |  25  | 7/8/2012  | true    |
| 3    |  25  | 15/8/2012 | true    |
| 4    |  25  | 19/8/2012 | false   |
| 5    |  25  | 25/8/2012 | true    |

data is in table like above but i need it like this:

| STID | ATDATE    | PRESENT |
..........................................................
|  null  | 1/8/2012   | null    |
|  null  | 2/8/2012   | null    |
..
..
|  25    | 6/8/2012   | true    |
|  25    | 7/8/2012   | true    |
..
..
|  null  | 30/8/2012  | null    |
|  25    | 31/8/2012  | true    |

Records are less than number of days in month but i need records depends on days in month, display records which are in table and other records should be dummy.

Answer 1

You will need to create a calendar table with an entry for every relevant day and use that to join to your attendances table.

 SELECT CalDate,STID,ATDATE,PRESENT 
 FROM Calendar
 LEFT JOIN Attendances
 ON Calendar.CalDate=Attendance.ATDATE    

This is just one of the many uses of a calendar table.