Sql server 爱奥尼茨。 | PK | FK1 | FK2 | ActionCode | CreationTS | SomeAttributeValue | +----+-----+-----+--------------+------------

爱奥尼茨。

| PK | FK1 | FK2 |   ActionCode |         CreationTS  | SomeAttributeValue |
+----+-----+-----+--------------+---------------------+--------------------+
|  6 | 100 | 500 |       Create | 2011-01-02 00:00:00 |                  H |
----------------------------------------------------------------------------
|  3 | 100 | 500 |       Change | 2011-01-01 02:00:00 |                  Z |
|  2 | 100 | 500 |       Change | 2011-01-01 01:00:00 |                  X |
|  1 | 100 | 500 |       Create | 2011-01-01 00:00:00 |                  Y |
----------------------------------------------------------------------------
|  4 | 100 | 510 |       Create | 2011-01-01 00:30:00 |                  T |
----------------------------------------------------------------------------
|  5 | 100 | 520 | CreateSystem | 2011-01-01 00:30:00 |                  A |
----------------------------------------------------------------------------

| FK1 | FK2 |   ActionCode | SomeAttributeValue |
+-----+-----+--------------+--------------------+
| 100 | 500 |       Create |                  H |
| 100 | 500 |       Create |                  Z |
| 100 | 510 |       Create |                  T |
| 100 | 520 | CreateSystem |                  A |
-------------------------------------------------

| PK | FK1 | FK2 |   ActionCode |         CreationTS  | SomeAttributeValue |
+----+-----+-----+--------------+---------------------+--------------------+
|  7 | 100 | 500 |       Change | 2011-01-02 02:00:00 |                  Z |
|  6 | 100 | 500 |       Create | 2011-01-02 00:00:00 |                  H |
|  2 | 100 | 500 |       Change | 2011-01-01 01:00:00 |                  X |
|  1 | 100 | 500 |       Create | 2011-01-01 00:00:00 |                  Y |
----------------------------------------------------------------------------

WITH partitioned AS (
  SELECT
    *,
    rn = ROW_NUMBER() OVER (PARTITION BY FK1, FK2 ORDER BY CreationTS)
  FROM data
),
subgroups AS (
  SELECT
    PK, FK1, FK2, ActionCode, CreationTS, SomeAttributeValue, rn,
    Subgroup = 1,
    Subrank  = 1
  FROM partitioned
  WHERE rn = 1
  UNION ALL
  SELECT
    p.PK, p.FK1, p.FK2, p.ActionCode, p.CreationTS, p.SomeAttributeValue, p.rn,
    Subgroup = s.Subgroup + CASE p.ActionCode WHEN 'Change' THEN 0 ELSE 1 END,
    Subrank  = CASE p.ActionCode WHEN 'Change' THEN s.Subrank ELSE 0 END + 1
  FROM partitioned p
    INNER JOIN subgroups s ON p.FK1 = s.FK1 AND p.FK2 = s.FK2
      AND p.rn = s.rn + 1
),
finalranks AS (
  SELECT
    PK, FK1, FK2, ActionCode, CreationTS, SomeAttributeValue, rn,
    Subgroup, Subrank,
    rank = ROW_NUMBER() OVER (PARTITION BY FK1, FK2, Subgroup ORDER BY Subrank DESC)
    /* or: rank = MAX(Subrank) OVER (PARTITION BY FK1, FK2, Subgroup) - Subrank + 1 */
  FROM subgroups
)
SELECT PK, FK1, FK2, ActionCode, CreationTS, SomeAttributeValue
FROM finalranks
WHERE rank = 1

;With Partitions as (
     Select
         t1.FK1,
         t1.FK2,
         t1.CreationTS as StartTS,
         t2.CreationTS as EndTS
     From
         Table t1
             left join
         Table t2
             on
                  t1.FK1 = t2.FK1 and
                  t1.FK2 = t2.FK2 and
                  t1.CreationTS < t2.CreationTS and
                  t2.ActionCode in ('Create','CreateSystem')
             left join
         Table t3
             on
                  t1.FK1 = t3.FK1 and
                  t1.FK2 = t3.FK2 and
                  t1.CreationTS < t3.CreationTS and
                  t3.CreationTS < t2.CreationTS and
                  t3.ActionCode in ('Create','CreateSystem')
       where
           t1.ActionCode in ('Create','CreateSystem') and
           t3.FK1 is null
), PartitionRows as (
     SELECT
         t1.FK1,
         t1.FK2,
         t1.ActionCode,
         t2.SomeAttributeValue,
         ROW_NUMBER() OVER (PARTITION_FRAGMENT_ID BY t1.FK1,T1.FK2,t1.StartTS ORDER BY t2.CreationTS desc) as rn
     from
         Partitions t1
             inner join
         Table t2
             on
                t1.FK1 = t2.FK1 and
                t1.FK2 = t2.FK2 and
                t1.StartTS <= t2.CreationTS and
                (t2.CreationTS < t1.EndTS or t1.EndTS is null)
)
select * from PartitionRows where rn = 1