Function query

Question

hi,
Using function need to find the student id is present in the table or not.
Is this right or i need to change the code. Please advice me
create or replace function stud_exist
(id in number)
return number
is
cnumber number;
cursor c1 is
select stu_id,stud_name from student_tb
where stud_id = id;
begin
open c1;
fetch c1 into cnumber;
if c1%found then
dmbs_output.put_line ("exist")
else
dbms_output.put_line ("notexist")
end if
close c1;
return cnumber;

Answer 1

Ramin Hashimzadeh wrote:
why you want to use function? if there is no way then i think this method is correct one:I DO NOT think, this is the CORRECT method..
CREATE OR REPLACE FUNCTION STUD_EXIST(ID IN NUMBER) RETURN NUMBER IS
CNUMBER NUMBER;
BEGIN
--"Why to use DUAL, EXISTS and all? Just select from the STUDENT_TAB"
--"Just add  one more filter( and rownum = 1) if you want to get rid of multiple records
SELECT ID
INTO CNUMBER
FROM DUAL
WHERE EXISTS
(SELECT STU_ID, STUD_NAME  --"Why two columns are selected here? What is the purpose?
FROM STUDENT_TB WHERE STUD_ID = ID);
RETURN CNUMBER;
EXCEPTION
WHEN NO_DATA_FOUND THEN
RETURN NULL;
END;