How to select rate for all selected modules and all selected years no matter they got rate for that year or not How to write a SQL to achieve the "goal" section?  Select rate for all selected modules and selected years no matter they got rate for that year or not.

The years and modules will be input by users, then the SQL will return the sum rate for selected years and selected modules.

For instance, Find rate for ASD,EB,GOF modules from 2008 till 2012, as the above

WITH finanimpact
     AS (SELECT Extract(YEAR FROM fiwm.create_dt) AS years,
                m.code                            AS mcode,
                SUM(fiwm.rate)                    AS rate
         FROM   master.financial_impact_wfins_mapping fiwm
                inner join master.wf_instance wf
                  ON wf.sysid = fiwm.wf_instance
                     AND wf.template_id = 4
                inner join master.wf_data_cr wdc
                  ON wdc.instance_id = fiwm.wf_instance
                inner join parameter.module m
                  ON m.sysid = wdc.module
                     AND m.sysid IN ( 4, 15, 6 )
         GROUP  BY Extract(YEAR FROM fiwm.create_dt),
                   m.code
         UNION
         (SELECT NULL,
                 m1.code,
                 0
          FROM   parameter.module m1
          WHERE  m1.sysid IN ( 4, 15, 6 )
          MINUS
          SELECT NULL,
                 m.code AS mcode,
                 0
          FROM   master.financial_impact_wfins_mapping fiwm
                 inner join master.wf_instance wf
                   ON wf.sysid = fiwm.wf_instance
                      AND wf.template_id = 4
                 inner join master.wf_data_cr wdc
                   ON wdc.instance_id = fiwm.wf_instance
                 inner join parameter.module m
                   ON m.sysid = wdc.module
                      AND m.sysid IN ( 4, 15, 6 )
          GROUP  BY Extract(YEAR FROM fiwm.create_dt),
                    m.code)) SELECT fi.years,
       fi.mcode,
       fi.rate
FROM   finanimpact fi
UNION
(SELECT LEVEL + 2008 - 1,
        '',
        0 AS id
 FROM   dual
 CONNECT BY LEVEL &lt;= 2012 - 2008 + 1
 MINUS
 (SELECT DISTINCT lfi.years,
                  '',
                  0
  FROM   finanimpact lfi)) 

returned result:
=========================
2008    null    0
2009    null    0
2010    EB  34640
2010    GOF 8660
2011    EB  103920
2011    GOF 12990
2012    null    0
null    ASD 0
=========================

goal:
=========================
2008    ASD     0
2009    ASD     0
2010    EB  34640
2010    GOF 8660
2011    EB  103920
2011    GOF 12990
2012    ASD 0
=========================
That looks like a homework question that is investigating how well you understand outer joins and maybe the NVL function (rather than the equijoins you currently have).