Technique show multiple rows in one single row with comma separate without using Repeater Controls

For example you have two columns in database School and Grades  like below

School                Grade
======             ========

M105                    01
M105                    02
M105                    03
M105                    04
M205                    05
M205                    02                    
M205                    01


And if you want to show these as a comma separated values like

School                 Grade
=======             ========
M105                    01,02,03,04
M205                    01,02,05

To achieve this with out using the repeater control in report to avoid performance issues follow this technique by creating a data source query subject in FM and use that in the report.

Oracle:

select
SCHOOL.SCHOOL_CODE ,
( listagg(SCHOOL.GRADE_NUMBER_CODE,', ')  within group

(order by SCHOOL.GRADE_NUMBER_CODE))  AS "GRADE"

from
ODS.SCHOOL  SCHOOL

group by

SCHOOL.SCHOOL_CODE


Enjoy
Kishore