Sliding certain records to the end of a run of the same date

Question

I have three columns -

• TheDate - Obviously a date.
• TheID - A strictly increasing ID.
• TheType - A Record t

Answer 1

This is complicated. First you must find consecutive date records, so with

thedate     theid  thetype
2014-07-12   5001       59
2014-07-12   5002      101
2014-07-12   5003       88
2014-07-13   5004       10
2014-07-12   5005       60

you would identify 2014-07-12 as one occurrence for the first three records and another for the last record. The second record would have to get position #3 in your results, not #5.

You achieve this by giving consecutive records a group key by using first LAG to look into the previous record, thus creating a flag on group change, and then cumulating these flags.

select thedate, theid, thetype
from
(
  select 
    thedate, theid, thetype,
    sum(new_group) over (order by theid) as group_key
  from
  (
    select
      thedate, theid, thetype,
      case when lag(thedate) over (order by theid) = thedate then 0 else 1 as new_group
    from mytable
  ) marked
) grouped
order by 
  group_key,
  case when thetype = 101 then 1 else 0 end,
  theid;