SQL Server stored procedure returns temporary records that doesn't exist

Question

I have a timesheet table records stored as follows in DetailsTbl :

ID   |  Day        | hours
----------------------------
 1   | 14/feb/14   |   8
 1   | 15/feb/14   |   8

And table called PAssign as follows:

 ID | from      | to
----------------------------------
 1  | 14/feb/14 | 17/feb/14

By executing the stored procedure, output should show:

ID | from      | to        | day       | Hours
------------------------------------------------
 1 | 14/feb/14 | 17/feb/14 | 14/feb/14 |  8
 1 | 14/feb/14 | 17/feb/14 | 15/feb/14 |  8
 1 | 14/feb/14 | 17/feb/14 | 16/feb/14 |  0
 1 | 14/feb/14 | 17/feb/14 | 17/feb/14 |  0

Only the null values where day between the from / to should be set to default which is ' 0 '

help appreciated

Answer 1

Taking a range and exploding it into multiple records can be done with a recursive CTE or a Numbers table . Here is an example using a recursive CTE:

;with cte as (
  select [id], [from], [to], [from] as day from PAssign
  union all
  select [id], [from], [to], [day]+1 from cte
  where [day] < [to]
)
select
  cte.id, cte.[from], cte.[to], cte.[day],
  coalesce(d.hours, 0) as hours
from cte
left join DetailsTbl d on cte.id = d.id and cte.day = d.day

Results ( DEMO )

| ID |                            FROM |                              TO |                             DAY | HOURS |
|----|---------------------------------|---------------------------------|---------------------------------|-------|
|  1 | February, 14 2014 00:00:00+0000 | February, 17 2014 00:00:00+0000 | February, 14 2014 00:00:00+0000 |     8 |
|  1 | February, 14 2014 00:00:00+0000 | February, 17 2014 00:00:00+0000 | February, 15 2014 00:00:00+0000 |     8 |
|  1 | February, 14 2014 00:00:00+0000 | February, 17 2014 00:00:00+0000 | February, 16 2014 00:00:00+0000 |     0 |
|  1 | February, 14 2014 00:00:00+0000 | February, 17 2014 00:00:00+0000 | February, 17 2014 00:00:00+0000 |     0 |

Turning this into a stored procedure should be pretty easy. Also note that a Recursive CTE makes use of one level of recursion per record generated, so you'll need to set the maximum recursion level as appropriate.