Fetch variable from cursor error in oracle pl sql - oracle

Question

I'm fetching value using cursor:
CURSOR Colcond
IS
SELECT CONDITION
FROM CONDITION_TAB
WHERE PROCEDURE_NAME = 'CALL_VOL';
In first iteration it would fetch "SUM(CASE WHEN CALL_REF=0 THEN 1 ELSE 0 END)".
In my program:
OPEN Colcond;
FETCH Colcond INTO cond_val;
SELECT Appnum, customer_num,'"cond_val"'
INTO iappnum, icustnum,icond_val
FROM CALL_DETAILS WHERE APPNUM = val_appl
AND customer_num = val_cust
Group by APPLICATION_NUM,CUST_SGMT_NUM,DNIS;
INSERT INTO S_CALL_VOLUME VALUES (iappnum, icustnum, SYSDATE, icond_val);
The record thRough the variable "icond_val" inserted is SUM(CASE WHEN CALL_REF=0 THEN 1 ELSE 0 END) instead of the value (10 or 20 or 50).
How to get the value instead of that Sum case statement?

Answer 1

You need to use dynamic SQL to incorporate the value you selected from the condition_tab table into the next query. Here's an example in an anonymous block rather than a procedure:
declare
val_appl number; -- procedure argument in your version?
val_cust number; -- procedure argument in your version?
query_string varchar2(2000);
cond_val condition_tab.condition%type;
iappnum call_details.appnum%type;
icustnum call_details.customer_num%type;
icond_val number;
cursordyn sys_refcursor;
cursor colcond is
select condition
from condition_tab
where procedure_name = 'CALL_VOL';
begin
open colcond;
fetch colcond into cond_val;
close colcond;
query_string:='select appnum, customer_num, ' || cond_val || ' from call_details '
|| 'where appnum = :val_appl and customer_num = :val_cust '
|| 'group by application_num,cust_sgmt_num,dnis';
open cursordyn for query_string using val_appl, val_cust;
fetch cursordyn into iappnum, icustnum, icond_val;
close cursordyn;
insert into s_call_volume values (iappnum, icustnum, sysdate, icond_val);
end;
/
Your column names seem to be a bit inconsistent so it probably needs some tweaking.
For both cursors you're only selecting one row, so (a) they don't really need to be cursors, they can just be select into statements; and (b) the second one is selecting the two columns from the where clause which seems a bit pointless - when you use iappnum in the insert, you could just use val_app, etc. So I think you could simplify this to:
declare
val_appl number; -- procedure argument in your version?
val_cust number; -- procedure argument in your version?
query_string varchar2(2000);
cond_val condition_tab.condition%type;
icond_val number;
begin
select condition
into cond_val
from condition_tab
where procedure_name = 'CALL_VOL';
query_string:='select ' || cond_val || ' from call_details '
|| 'where appnum = :val_appl and customer_num = :val_cust '
|| 'group by application_num,cust_sgmt_num,dnis';
execute immediate query_string into icond_val using val_appl, val_cust;
insert into s_call_volume values (val_appl, val_cust, sysdate, icond_val);
end;
/
This will error if either query doesn't return exactly one row. Your cursor version will error if the condition_tab query finds no data, and will only use one 'condition' if there are multiples; and will only use the first result from the second query if there are multiples. If you're expecting multiples from either (not sure what your actual grouping is supposed to be, it looks inconsistent too) then you need to loop over the cursor, fetching repeatedly.
Hopefully this will get you started though.