Show custom message when no rows selected in procedure [duplicate] - oracle

Question

I have a following stored procedure in which I have used a cursor. Depending on whether the cursor return any records or not I need to do some processing.
But I am not sure how to check if the cursor return any records.
CREATE OR REPLACE PROCEDURE SP_EMPLOYEE_LOOKUP_BY_EMP_ID
(
IN_USER_ID IN NUMBER,
IN_EMPLOYEE_ID NUMBER,
IN_HC_AS_ON_DATE VARCHAR2,
emp_cursor OUT SYS_REFCURSOR
)
IS
CURSOR employees IS
SELECT * FROM EMPLOYEE e;
BEGIN
if(record exist ) then
FOR employee IN employees
LOOP
// do something
END LOOP;
else if employees is empty then
// do something else
END;

Answer 1

It's not possible to check if the cursor returns records without opening it.
(see here)
So you can either have some fast query just to see if there are records (using count for example),
Or, you can do it like this:
CREATE OR REPLACE PROCEDURE SP_EMPLOYEE_LOOKUP_BY_EMP_ID
(
IN_USER_ID IN NUMBER,
IN_EMPLOYEE_ID NUMBER,
IN_HC_AS_ON_DATE VARCHAR2,
emp_cursor OUT SYS_REFCURSOR
)
IS
is_found_rec boolean := false;
CURSOR employees IS
SELECT * FROM EMPLOYEE e;
BEGIN
FOR employee IN employees
LOOP
is_found_rec := true;
// do something
END LOOP;
if not is_found_rec then
// do something else
end if;
END;

Answer 2

I think that it possible only with FETCH. Try to use
if myCursor%found then
// some body
end if;
But if somebody know another way so correct me.

Answer 3

I like this way:
DECLARE
CURSOR my_cur
IS
SELECT 'a' AS a FROM DUAL WHERE 1=1;
my_rec my_cur%rowtype;
BEGIN
OPEN my_cur;
LOOP
FETCH my_cur INTO my_rec;
IF my_cur%NOTFOUND
THEN
IF my_cur%ROWCOUNT=0
THEN
-- do stuff when cursor empty
DBMS_OUTPUT.PUT_LINE('NOTFOUND,RC=0' || '_' || my_cur%ROWCOUNT || '_' || my_rec.a);
END IF;
EXIT;
ELSE
-- do stuff when cursor not empty
DBMS_OUTPUT.PUT_LINE('FOUND,RC>0' || '_' || my_cur%ROWCOUNT || '_' || my_rec.a);
END IF;
END LOOP;
CLOSE MY_CUR;
END;
Output when cursor is 1=1 (not empty):
FOUND,RC>0_1_a
Output when cursor is 1=0 (empty):
NOTFOUND,RC=0_0_

Answer 4

I like to use the same select query that comprises the cursor and select the count it returns into a variable. You can then evaluate the variable to determine what to do next. For example you have a cursor like this:
CURSOR c_example IS
SELECT field1
,field2
,field3
FROM table1 a
WHERE a.field1 LIKE '%something%';
Before you open the cursor to do any processing, select cursor result count into a variable.
SELECT count(*)
INTO v_exampleCount
FROM table1 a
WHERE a.field1 LIKE '%something%';
Now, again before you open cursor, do something like:
IF exampleCount>0 THEN
FOR example IN c_example
LOOP
....
END LOOP; --end example loop
....
END IF; --end example if

Answer 5

341/5000
One solution would be to work with reverse logic. It is e.g. not possible to ask:
IF my_record IS NULL THEN
do something;
END IF;
or
IF my_record.my_attibute IS NULL THEN
do something;
END IF;
Instead it is possible to ask:
IF my_record.my_attibute IS NOT NULL THEN
go on processing;
ELSE
do something;
END IF;