PL/SQL exception-handling - if-statement

Question

I have PL/SQL anonymous block to work with finding an employees based on their department_id. I wrote a procedure for that.
Code
CREATE OR REPLACE PROCEDURE find_employees (
p_dept_no IN NUMBER,
p_error_message OUT VARCHAR2)
AS
v_dept_no NUMBER;
dept_chk EXCEPTION;
CURSOR find_emp
IS
SELECT employee_id,
first_name,
last_name,
salary,
hire_date
FROM employees
WHERE department_id = p_dept_no;
BEGIN
-- Check if the department_id in departments table
IF Condition
THEN --Need to check the condition here
RAISE dept_chk;
END IF;
FOR i IN find_emp
LOOP
DBMS_OUTPUT.put_line (i.employee_id);
DBMS_OUTPUT.put_line (i.first_name);
DBMS_OUTPUT.put_line (i.last_name);
DBMS_OUTPUT.put_line (i.salary);
DBMS_OUTPUT.put_line (i.hire_date);
END LOOP;
EXCEPTION
WHEN dept_chk
THEN
p_error_message := 'Please enter valid department number';
END find_employees;
How to check if the department_id in departments table
Note:
On that procedure there is one input parameter p_dept_no as INPUT
and p_error_message is the output parameter.
I need to check the if the department_id is in in the departments table then automatically the records will show other wise it's showing an exception so there i need to check the condition how it's possible let me know Thanks in advance.

Answer 1

Given that you already scan the table, you can simply set a variable in within the loop and check its value outside.
For example:
CREATE OR REPLACE PROCEDURE find_employees(p_dept_no IN
NUMBER,p_error_message OUT VARCHAR2)
AS
v_dept_no NUMBER;
dept_chk EXCEPTION;
vEmployeeFound boolean := false; -- a boolean variable
CURSOR find_emp
IS
SELECT
employee_id, first_name, last_name, salary, hire_date
FROM
employees
WHERE
department_id = p_dept_no;
BEGIN
FOR i in find_emp
LOOP
dbms_output.put_line(i.employee_id);
dbms_output.put_line(i.first_name);
dbms_output.put_line(i.last_name);
dbms_output.put_line(i.salary);
dbms_output.put_line(i.hire_date);
vEmployeeFound := true; -- set the variable
END LOOP;
-- Check if the department_id in departments table
IF NOT vEmployeeFound THEN -- check the variable value
RAISE dept_chk;
END IF;
EXCEPTION
WHEN dept_chk THEN
p_error_message:='Please enter valid department number';
END find_employees;