Adding conditionals to PL/SQL cursors - oracle

Question

In the below PL/SQL program I have 2 cursors that are almost similar in functionality. I'm not sure, how I can retain the same functionality just by having one cursor and get rid of the get_all_employes cursor which doesn't have the where clause.
Thanks in advance for your time and help!
CREATE OR REPLACE PROCEDURE EMP_DETAILS(dept_id VARCHAR2) IS
CURSOR get_all_employes IS
SELECT EMP_ID, EMP_NAME, EMP_SAL, EMP_DEPT FROM EMP;
CURSOR get_employee_info IS
SELECT EMP_ID, EMP_NAME, EMP_SAL, EMP_DEPT FROM EMP WHERE EMP_DEPT = dept_id;
BEGIN
IF dept_id IS NULL THEN
FOR X IN get_all_employes;
DBMS_OUTPUT.PUT_LINE(X.EMP_ID || ' ' || X.EMP_NAME || ' ' || X.EMP_SAL || X.EMP_DEPT);
END LOOP;
ELSE
FOR Y IN get_all_employes;
DBMS_OUTPUT.PUT_LINE(Y.EMP_ID || ' ' || Y.EMP_NAME || ' ' || Y.EMP_SAL || Y.EMP_DEPT);
END LOOP;
END IF;
END EMP_DETAILS;
/

Answer 1

Use one cursor and include WHERE EMP_DEPT = dept_id OR dept_id IS NULL:
CREATE PROCEDURE EMP_DETAILS(
dept_id IN EMP.EMP_DEPT%TYPE
)
IS
CURSOR get_employee_info IS
SELECT EMP_ID,
EMP_NAME,
EMP_SAL,
EMP_DEPT
FROM EMP
WHERE EMP_DEPT = dept_id
OR dept_id IS NULL;
BEGIN
FOR Y IN get_employee_info LOOP
DBMS_OUTPUT.PUT_LINE(Y.EMP_ID || ' ' || Y.EMP_NAME || ' ' || Y.EMP_SAL || Y.EMP_DEPT);
END LOOP;
END EMP_DETAILS;
/
So, for the test data:
CREATE TABLE emp ( EMP_ID, EMP_NAME, EMP_SAL, EMP_DEPT ) AS
SELECT 1, 'a', 100, 1 FROM DUAL UNION ALL
SELECT 2, 'b', 200, 1 FROM DUAL UNION ALL
SELECT 3, 'c', 300, 2 FROM DUAL;
Then:
BEGIN
emp_details( NULL );
END;
/
Would output all the rows:
1 a 1001
2 b 2001
3 c 3002
and:
BEGIN
emp_details( 1 );
END;
/
would output only the rows for department 1:
1 a 1001
2 b 2001
db<>fiddle here

Answer 2

Try something like this (fyi your example code does not compile)
create or replace PROCEDURE EMP_DETAILS(dept_id VARCHAR2) IS
TYPE EmpCurTyp IS REF CURSOR;
emp_cv EmpCurTyp;
empRec EMP%ROWTYPE;
BEGIN
IF dept_id IS NULL THEN
open emp_cv for SELECT EMP_ID, EMP_NAME, EMP_SAL, EMP_DEPT FROM EMP;
ELSE
open emp_cv for SELECT EMP_ID, EMP_NAME, EMP_SAL, EMP_DEPT FROM EMP WHERE EMP_DEPT = dept_id;
END IF;
LOOP
FETCH emp_cv INTO empRec;
IF emp_cv%NOTFOUND
THEN
EXIT;
END IF;
DBMS_OUTPUT.PUT_LINE(empREc.EMP_ID || ' ' || empREc.EMP_NAME || ' ' || empREc.EMP_SAL || empREc.EMP_DEPT);
END LOOP;
CLOSE emp_cv;
END EMP_DETAILS;