Cursor Select statement Where condition changes based on condition - oracle

Question

I am using a Cursor in a procedure, here I am not using Bulk collect since I have lot of calculations on the records fetched from Cursor.
In Cursor's Select statement Where clause changes based on condition , I am trying to use the code as below but it is giving me error:
Error(19,12): PLS-00103: Encountered the symbol "c_recs" when expecting one of the following: := . ( # % ;
create or replace PROCEDURE "test"
(fromdate_in IN varchar2,
todate_in IN varchar2,
atype_in IN number
)
is
begin
if atype_in = 01 then
cursor c_recs IS SELECT cname FROM A_AUD AA WHERE AA.atime BETWEEN to_date( '' || fromdate_in || '' ,'DD/MM/RRRR')
AND to_date('' || todate_in || '','DD/MM/RRRR') AND AA.CTYPE IN ('RAlert');
elsif atype_in = 02
cursor c_auditrecs IS SELECT cname FROM A_AUD AA WHERE AA.atime BETWEEN to_date( '' || fromdate_in || '' ,'DD/MM/RRRR')
AND to_date('' || todate_in || '','DD/MM/RRRR') AND AA.CTYPE IN ('DAlert');
end if;
end
begin
--more logic
FOR rec IN c_recs LOOP
---calculations
END LOOP;
END test;
I do not want to use SYS_REFCURSOR as from net , i read cursors are slight better than ref cursors.

Answer 1

A better and efficient option would be to do it in a single statement without any CURSORs. But, it does depend on what you want to do.If you have to do dmls based on the cursor records, preferably do it in a single statement.
If indeed you want to process something in a loop, use an implicit cursor loop which is equivalent ( and sometimes better performant ) to explicit cursors.
The select query can also be simplified with conditional logic rather than IF/ELSE.
CREATE OR REPLACE PROCEDURE "test" (
fromdate_in IN VARCHAR2,
todate_in IN VARCHAR2,
atype_in
in NUMBER
) is begin
for cur in (
SELECT cname
FROM a_aud aa
WHERE aa.time BETWEEN TO_DATE(fromdate_in,'dd/mm/rrrr')
AND TO_DATE(todate_in,'dd/mm/rrrr') AND (
(
atype_in = '01' AND aa.ctype = 'RAlert'
) OR (
atype_in = '02' AND aa.ctype = 'DAlert'
)
)
) loop
---calculations
do_something_with(cur.cname)
end loop;
end;
/
I would also suggest you to have the type of arguments as dates and pass the variables directly from the calling block rather than converting them inside the sql/cursor.This will avoid TO_DATE conversion.

Answer 2

CASE in cursor declaration solves that problem:
DECLARE
CURSOR c_recs
IS
SELECT cname
FROM a_aud aa
WHERE aa.time BETWEEN TO_DATE (fromdate_in, 'dd/mm/rrrr')
AND TO_DATE (todate_in, 'dd/mm/rrrr')
AND aa.ctype =
CASE
WHEN atype_in = '01' THEN 'RAlert'
WHEN atype_in = '02' THEN 'DAlert'
END;
BEGIN
FOR rec IN c_recs
LOOP
NULL;
END LOOP;
END;
I can't comment your refcursor statement.