Question

I am new with these oracle dynamic queries, I am just trying to build a dynamic query, so I could get records according to it.

Here is my PL/ SQL statement:

declare
sql_query varchar2(5000) := 'select FKOM_OFFICE_ID,FKBAM_BUDGET_ID ';
begin
for x in (select distinct PFS_SOURCE_ID,PFS_SOURCE_ENG from PBS_FC_SOURCE WHERE PFS_UPPER_SOURCE_ID!=0 ORDER BY PFS_SOURCE_ID ASC )
loop
    sql_query := sql_query ||
        ' , nvl(sum(case when FKBAB_SOURCE_ID = '||x.PFS_SOURCE_ID||' then FKOD_AMOUNT ELSE 0 end),0) as source_'||x.PFS_SOURCE_ID;
        dbms_output.put_line(sql_query);
end loop;
sql_query := sql_query || ' FROM FMS_K_OFFICEWISE_DTL
JOIN FMS_K_OFFICEWISE_MST ON FMS_K_OFFICEWISE_MST.FKOM_OFFICE_MST_ID=FMS_K_OFFICEWISE_DTL.FKOD_OFFICE_MST_ID
JOIN FMS_K_BUDGET_ALLOCATION_DTL ON FMS_K_BUDGET_ALLOCATION_DTL.FKBAD_BUDGET_ALLOC_DTL_ID=FMS_K_OFFICEWISE_DTL.FKOD_BUDGET_ALLOC_AD_ID
JOIN FMS_K_BUDGET_ALLOCATION_MST ON FMS_K_BUDGET_ALLOCATION_MST.FKBAM_BUDGET_ALLOC_ID=FMS_K_BUDGET_ALLOCATION_DTL.FKBAB_BUDGET_ALLOC_ID
JOIN PBS_FC_BUDGET ON PBS_FC_BUDGET.PFB_BUDGET_ID=FMS_K_BUDGET_ALLOCATION_MST.FKBAM_BUDGET_ID    
WHERE PFB_LEVEL_ID=2 GROUP BY FKOM_OFFICE_ID,FKBAM_BUDGET_ID ';
dbms_output.put_line(sql_query);
end;

How to get records from this above statement since I hope the query seems fine ?

Answer 1

One possibility is using a ref cursor – you build your SQL statement and open the ref cursor for this statement afterwards.

Simplified:

declare
  l_cursor sys_refcursor;
  sql_query varchar2(4000);
begin
  sql_query := 'select 1 as value from dual';
  open l_cursor for sql_query;
end;

Depending on your IDE / host language, you can then iterate over the cursor etc.

For example, to print a ref cursor in SQL Plus:

variable x refcursor
set autoprint on
declare
  sql_query varchar2(4000);
begin
  sql_query := 'select 1 as value from dual';
  open :x for sql_query;
end;

This concept is even more powerful in 11g, because you can

• use a CLOB for the SQL statement (thus allowing you to dynamically generate queries of arbitrary length)
• convert a ref cursor to a DBMS_SQL cursor (and vice versa), which gives you much more flexibility if you need to get the column count and column types at runtime