Spliting rows into multiple rows based on time interval

Question

Hi experts need your help for framing query for the below scenarios
Scenario 1
Query should check for priority record(25), if the start_date and end_date of that priority record is the max in that group, records will not have any split.
output will be the same.
DC Store St Date End date Priority
955 3 1/1/2010 12/31/9999 25
966 3 4/5/2011 10/10/2011 50
977 3 10/12/2011 12/12/2012 100
output
DC store St Date End date Priority Rank
955 3           1/1/2010 12/31/9999 25 1
966 3           4/5/2011 10/10/2011 50 2
977 3           10/12/2011 12/12/2012 100 3
Scenario 2
If priority record is not covering the max range, then split the records as shown below,
1. during the time period 1/1/2011 & 4/30/2011 there were no other DC for that store so rank would be 1
2. the next range would be 5/1/2011 to 6/29/2011 we have 2 records in service so the record with low priortiy would be ranked 1 and second priority would be ranked 2
3. similarly, for 6/30/2011 to 10/1/2011 we have 3 records in service and it will be ranked accordingly on the priority.
DC Store St Date End date Priority
966 3 6/30/2011 10/1/2011 25
955 3 5/1/2011 11/30/2011 50
977 3 1/1/2011 12/31/2011 100
output
DC store St Date End date Priority Rank
977 3 1/1/2011 4/30/2011 100 1
955 3 5/1/2011 6/29/2011 50 1
977 3 5/1/2011 6/29/2011 100 2
966 3 6/30/2011 10/1/2011 25 1
955 3 6/30/2011 10/1/2011 50 2
977 3 6/30/2011 10/1/2011 100 3
955 3 10/2/2011 11/30/2011 50 1
977 3 10/2/2011 11/30/2011 100 2
977 3 12/1/2011 12/31/2011 100 1
Scenario 3
This works similar to scenario 2
DC Store St Date End date Priority
966 3 2/1/2011 12/31/2011 25
955 3 1/1/2011 12/31/2012 50
977 3 5/1/2011 06/31/2011 100
output
DC store St Date End date Priority Rank
955 3 1/1/2011 1/31/2011 50 1
966 3 2/1/2011 12/31/2011 25 1
955 3 2/1/2011 12/31/2011 50 2
977 3 5/1/2011 6/30/2011 100 3
955 3 1/1/2012 12/31/2012 50 1
Note: the number of rows coming in input will be dynamic and there are possibilities for the date ranges to overlap.

Answer 1

Hi,
Sorry, your requirement are unclear.
What role do dc, store and priority play in this problem? Prioriry obviously has something to do with how rows are split. Why is priority=25 special? Does the number 25 have some speciakl meaning, or does it just happen to be the lowest value of priority? Can 2 (or more) rows have the same priority? if so, can their dates overlap? Include examples in your sample data and results.
I think you want something like this:
WITH     all_dates     AS
     SELECT     st_date          AS a_date
     ,     priority
     FROM     table_x
    UNION ALL
     SELECT     end_date + 1     AS a_date
     ,     priority
     FROM     table_x
,     got_break_date     AS
     SELECT       a_date
     ,       LEAD (a_date) OVER (ORDER BY a_date)     AS next_date
     ,       MIN (priority)                     AS min_priority
     FROM       all_dates
     GROUP BY  a_date
,     paired_data     AS
     SELECT       x.*
     ,       b.*
     ,       GREATEST ( x.st_date
                       , b.a_date
                  )          AS s_date
     ,       LEAST ( x.end_date
                   , b.next_date
               )          AS e_date
     ,       RANK () OVER ( PARTITION BY  GREATEST (x.st_date, b.a_date)
                                   ORDER BY      x.priority
                      )        AS rnk
     FROM     table_x          x
     JOIN     got_break_date     b  ON   b.a_date     >= x.st_date
                       AND     b.a_date         <  x.end_date
                       AND     b.min_priority  <= x.priority
SELECT       dc
,       store
,       s_date          AS st_date
,       e_date - CASE
                   WHEN  rnk     = 1
                 AND   end_date     = e_date
                 THEN  0
                 ELSE  1
               END          AS end_date
,       priority
,       rnk
FROM       paired_data
ORDER BY  s_date
,            priority
I hope this answers your question.
If not, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only), and the results you want from that data, formatted, between \ tags.  See the froum FAQ {message:id=9360002}
Point out where the results of the query above are wrong, and explain, using specific examples, how you get those results from the given data in those places.
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