Converting rows to columns in ORACLE SQL with parametrization

Question

For one of my ETL-Jobs I need a SQL-Query that converts rows to columns. The difficulty is that I want to parameterize how many rows getting converted into one column as shown in following example:

ATM my scenario looks like this:

Oracle 11g

One Column Table:

PARAMETER

AB

AE

CF

GH

5G

H3

7P

…..

SQL-Query:

SELECT listagg (''''
  ||PARAMETER
  ||'''', ',') WITHIN GROUP (
ORDER BY ROWNUMBER) AS PARAMETER,
FROM
  (SELECT
    CASE
      WHEN ROWNUM <= 5 THEN 5
      WHEN ROWNUM <= 10 THEN 10
      WHEN ROWNUM <= 15 THEN 15
      WHEN ROWNUM <= 20 THEN 20
      WHEN ROWNUM <= 25 THEN 25
    END AS ROWNUMBER
    PARAMETER
  FROM SR0_CRTL_SL_OL_PSM_PARAMETER
  )
GROUP BY ROWNUMBER

Result would look like this:

PARAMETER

AB, BG, RT, ZH, JK

AE, HL, GH, DZ, KL

CF, GH, NM, SD, WE …..

What I would like to have is a Query that takes a number eg. 5 with the following result:

PARAMETER

AB, BG, RT, ZH, JK

AE, HL, GH, DZ, KL

CF, GH, NM, SD, WE …..

Or it takes eg. 8 and the result would be like:

PARAMETER

AB, BG, RT, ZH, JK, AE, HL, GH

DZ, KL, CF, GH, NM, SD, WE, DE

FG, JK, KL, UZ, IT, FG, HR, TZ …..

I hope you get what I mean. Maybe someone could provide me some help.

Thanks

PS: I know that my English is damn good “: }

Answer 1

You can calculate the group using arithmetic -- do a division and take the integer from it. The following uses "8" as the parameter:

SELECT listagg (''''||PARAMETER||'''', ',') WITHIN GROUP (ORDER BY RowNumber) AS PARAMETER,
FROM (SELECT trunc((rownum - 1) / 8) as grp, t.*,
             rownum as RowNumber
      FROM SR0_CRTL_SL_OL_PSM_PARAMETER t
     ) t
GROUP BY grp;