ORA-01403: no data found - sql

Question

I've a SQL query where if output is NULL it should not send warning .
l_sup_id NUMBER;
begin
SELECT per_all_assignments_f.supervisor_id
INTO l_sup_id
FROM per_all_assignments_f
WHERE person_id = p_person_id
AND trunc (sysdate) BETWEEN effective_start_date
AND effective_end_date
AND primary_flag = 'Y';
elsif (p_person_type = 'APPRAISER' AND l_sup_id IS NOT NULL) then
hr_utility.set_message(801, 'HR_51888_APR_APPRAISER_NULL');
hr_utility.raise_error;
end if;
Whenever l_sup_id is null according to logic
hr_utility.set_message(801, 'HR_51888_APR_APPRAISER_NULL');
should not be executed
But whenever l_sup_id is null I am getting
ORA-01403: no data found
error in logs
If l_sup_id is not null application working is fine

Answer 1

From documentation,
NO_DATA_FOUND
A SELECT INTO statement returns no rows, or your program references a
deleted element in a nested table or an uninitialized element in an
index-by table.
In your PL/SQL code, the SELECT .. INTO statement returns no rows, thus it raises NO_DATA_FOUND error. It never goes to the next line, i.e. your IF-ELSE construct.
If you want to continue the operation, then you need to handle the EXCEPTION gracefully.
For example,
SQL> SET serveroutput ON
SQL>
SQL> DECLARE
2 o_ename emp.ename%TYPE;
3 i_empno emp.empno%TYPE;
4 BEGIN
5 SELECT ename INTO o_ename FROM emp WHERE empno = i_empno;
6 -- Handle no_data_found
7 EXCEPTION
8 WHEN no_data_found THEN
9 -- do something
10 dbms_output.put_line('No records found for employee no '|| i_empno);
11 END;
12 /
No records found for employee no
PL/SQL procedure successfully completed.
SQL>

Answer 2

As the error suggests its pointing to NO DATA for the condition, to handle that you need to use "Exception Handling", Please see the code for the changes,
declare
l_sup_id NUMBER;
begin
SELECT per_all_assignments_f.supervisor_id
INTO l_sup_id
FROM per_all_assignments_f
WHERE person_id = p_person_id
AND trunc (sysdate) BETWEEN effective_start_date
AND effective_end_date
AND primary_flag = 'Y';
elsif (p_person_type = 'APPRAISER' AND l_sup_id IS NOT NULL) then
hr_utility.set_message(801, 'HR_51888_APR_APPRAISER_NULL');
hr_utility.raise_error;
end if;
--changes start
exception
when no_Data_found then
dbms_output.put_line('No data exists for lsup '|| l_sup_id)
--changes end
end;
Edit:
SQL> SELECT * FROM TESTEMP WHERE EMPNO=6677;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
6677 JUPITER CLERK 7902 17-DEC-80 800 20
SQL>
SQL> declare
2 l_count number;
3 begin
4 select comm into l_count from testemp where empno=6677 ;
5 DBMS_OUTPUT.PUT_LINE('lcount is'||l_count);
6 if (l_count IS NULL) then
7 dbms_output.put_line('no data');
8 else
9 dbms_output.put_line('data');
10 end if;
11 end;
12 /
lcount is
no data
PL/SQL procedure successfully completed.
Your condition wont go into the if at all if you compare to NULL or how ever you want to use it according to your specification

Answer 3

Thank you for all the responses.
Instead of plain sql I created the following cursor
cursor csr_supervisor_id
is
SELECT supervisor_id
FROM per_all_assignments_f
WHERE person_id = p_person_id
AND trunc (sysdate) BETWEEN effective_start_date
AND effective_end_date
AND primary_flag = 'Y';
and fetched it in l_sup_id
open csr_supervisor_id;
fetch csr_supervisor_id into l_sup_id;
Now no data received error is not coming.