Question

Lets say we have a table here, populated with the following data:

acc_id1  acc_id2  acc_grp_id1  acc_parameter1  acc_parameter2
111      111111   115          1               155
111      111111   116          2               166
222      222222   216          2               167
222      222222   217          2               168
333      333333   316          3               155
334      333333   317          3               169
444      444444   416          4               151
445      444444   417          2               166

Every account has multiple acc_ids, but the parameter codes are fixed. I am trying to retrieve only those accounts which follow this rule: if the biggest (latest) acc_grp_id1 has param1 = 2 and param2 = 166, both rows should be present. If the biggest (latest) parameters are equal to different codes, populate only the latest one.

This is how it should look:

acc_id1  acc_id2  acc_grp_id1  acc_parameter1  acc_parameter2
111      111111   115          1               155
111      111111   116          2               166
222      222222   217          2               168
334      333333   317          3               169
444      444444   416          4               151
445      444444   417          2               166

The actual output is a join from 5 tables.

Any ideas would be appreciated.

Answer 1

Try this(not tested):

WITH FullData AS
(
    SELECT  a.*,
            ROW_NUMBER() OVER(PARTITION BY acc_id2 ORDER BY acc_grp_id1 DESC) AS Position
      FROM  <YOUR-TABLE> a
), FilteredData AS
(
    SELECT  *
      FROM  FullData
     WHERE  Position = 1 
       AND  acc_parameter_1 = 2 
       AND  acc_parameter_2 = 166
)
SELECT  a.*
  FROM  FullData a LEFT JOIN FilteredData b
        ON  a.acc_id2 = b.acc_id2
 WHERE  (b.acc_id2 IS NULL AND a.Position = 1) -- Should be a.Position instead of b.Position
    OR  b.acc_id2 IS NOT NULL