Date range SQL

Question

I have a 2 tables table like this:
Employee Table
emp_id  region  active_date
A100    01      8/19/2009
A100    01      8/21/2009
A100    01      8/27/2009
A100    01      9/2/2009
A100    01      10/1/2009
A100    01      3/27/2010
Date_Lkp Table
Date_sk     Start_dt     End_date     
1     7/15/2009     8/14/2009
2     8/15/2009     9/14/2009
3     9/15/2009     10/14/2009
4     10/15/2009     11/14/2009
5     11/15/2009     12/14/2009
6     12/15/2009     1/14/2010
7     1/15/2010     2/14/2010
8     2/15/2010     3/14/2010
9     3/15/2010     4/14/2010I need an ouput like this:
emp_id  region  Start_dt     End_date     Date_sk
A100    01      8/19/2009     9/14/2009     2
A100    01      9/15/2009     10/14/2009     3
A100    01      3/15/2010     4/14/2010     9Records with SK 1,4-8 are not there because we dont have the employee active during that time. Also pls note that start date of the 1st record in output is same as the employee's Active start date.
Thanks.
Edited by: user572405 on Dec 1, 2010 1:28 PM

Answer 1

So you want Active_Date be selected as the start date for all records ?
select empid, region,  case when c > 1 then min(active_date)
                                else min(start_dt) end as start_dt,
                                end_dt, date_sk
from (                               
select empid, region,  start_dt, end_dt, date_sk, active_date, count(date_sk) over (partition by empid, region, start_dt, end_dt) c
from (
         select 'A100' empid,    '01' region,      to_date('8/19/2009', 'MM/DD/RRRR') active_date from dual union all
         select 'A100',    '01',      to_date('8/21/2009', 'MM/DD/RRRR') from dual union all
         select 'A100',    '01',      to_date('8/27/2009', 'MM/DD/RRRR') from dual union all
         select 'A100',    '01',      to_date('9/2/2009', 'MM/DD/RRRR') from dual union all
         select 'A100',    '01',      to_date('10/1/2009', 'MM/DD/RRRR') from dual union all
         select 'A100',    '01',      to_date('3/27/2010', 'MM/DD/RRRR') from dual
) m,
        select 1 date_sk,    to_date('7/15/2009', 'MM/DD/RRRR') start_dt,    to_date('8/14/2009', 'MM/DD/RRRR') end_dt from dual union all
        select 2,    to_date('8/15/2009', 'MM/DD/RRRR'),    to_date('9/14/2009', 'MM/DD/RRRR') from dual union all
        select 3,    to_date('9/15/2009', 'MM/DD/RRRR'),    to_date('10/14/2009', 'MM/DD/RRRR') from dual union all
        select 4,    to_date('10/15/2009', 'MM/DD/RRRR'),    to_date('11/14/2009', 'MM/DD/RRRR') from dual union all
        select 5,    to_date('11/15/2009', 'MM/DD/RRRR'),       to_date('12/14/2009', 'MM/DD/RRRR') from dual union all
        select 6,    to_date('12/15/2009', 'MM/DD/RRRR'),       to_date('1/14/2010', 'MM/DD/RRRR') from dual union all
        select 7,    to_date('1/15/2010',  'MM/DD/RRRR'),    to_date('2/14/2010', 'MM/DD/RRRR') from dual union all
        select 8,    to_date('2/15/2010',  'MM/DD/RRRR'),      to_date('3/14/2010', 'MM/DD/RRRR') from dual union all
        select 9,    to_date('3/15/2010',  'MM/DD/RRRR'),      to_date('4/14/2010', 'MM/DD/RRRR') from dual
) d
where active_date between start_dt and end_dt
group by empid, region,  end_dt, date_sk, c
order by 3And the result is:
DATE_SK REGION  START_DT    END_DT      DATE_SK
A100        01  8/19/2009   9/14/2009       2
A100        01  9/15/2009   10/14/2009      3
A100        01  3/15/2010   4/14/2010       9Edited by: Zaafran Ahmed on Dec 1, 2010 4:04 PM