cannot reference to cursor instances oracle pl/sql - oracle

Question

CREATE OR REPLACE PROCEDURE employee_info_all_in_one
(p_id IN NUMBER)
IS
CURSOR c_city IS
(SELECT l.city
FROM employees e
INNER JOIN departments d
ON (e.department_id = d.department_id)
INNER JOIN locations l
ON (l.location_id = d.location_id)
WHERE e.employee_id = p_id);
CURSOR c_manager IS
(SELECT e1.last_name
FROM employees e1
INNER JOIN
employees e2
ON (e1.employee_id = e2.manager_id)
WHERE e2.employee_id = p_id);
CURSOR c_department_name IS
(SELECT department_name
FROM employees e
INNER JOIN
departments d
ON (e.department_id = d.department_id)
WHERE e.employee_id = p_id);
TYPE EmpRecTyp IS RECORD
( v_annual_sal NUMBER(9,2),
v_monthly_sal NUMBER(9,2),
v_last_name VARCHAR2(10),
v_deptno NUMBER(3),
v_length NUMBER(2),
v_tenure NUMBER(5),
v_job_id VARCHAR2(20),
v_hire_date DATE,
v_city VARCHAR(25),
v_commission_pct NUMBER(2,2),
v_phone_number VARCHAR2(20),
v_manager VARCHAR2(20),
v_comm_calc NUMBER(10,2),
v_email VARCHAR2(10),
v_department VARCHAR2(20),
v_count NUMBER(4)
);
TYPE EmpRecTyp IS REF CURSOR;
emp_c_v EmpRecTyp;
BEGIN
DBMS_OUTPUT.PUT_LINE('Welcome to the summary of an employee based on his unique id');
DBMS_OUTPUT.PUT_LINE('============================================================');
SELECT salary, last_name, department_id,
TRUNC(MONTHS_BETWEEN(SYSDATE,hire_date),0), job_id,
hire_date, commission_pct, phone_number, email
INTO emp_c_v.v_monthly_sal, emp_c_v.v_last_name, emp_c_v.v_deptno,
emp_c_v.v_tenure, emp_c_v.v_job_id, emp_c_v.v_hire_date, emp_c_v.v_commission_pct,
emp_c_v.v_phone_number, emp_c_v.v_email
FROM employees
WHERE employee_id = p_id;
emp_c_v.v_count := SQL%ROWCOUNT;
DBMS_OUTPUT.PUT_LINE(emp_c_v.v_count||' row retrieved...');
DBMS_OUTPUT.PUT_LINE('=============================');
emp_c_v.v_annual_sal := emp_c_v.v_monthly_sal * 12;
emp_c_v.v_length := LENGTH(emp_c_v.v_last_name);
DBMS_OUTPUT.PUT_LINE('Employee:-> ' || emp_c_v.v_last_name || ' ,and his name contains: ' || emp_c_v.v_length ||' chars');
DBMS_OUTPUT.PUT_LINE('=============================');
DBMS_OUTPUT.PUT_LINE(q'[Belong's to department: ]' || emp_c_v.v_deptno);
DBMS_OUTPUT.PUT_LINE('=============================');
IF (emp_c_v.v_monthly_sal < emp_c_v.v_annual_sal)
THEN
DBMS_OUTPUT.PUT_LINE('Has a annual salary of:-> ' || emp_c_v.v_annual_sal);
ELSE
DBMS_OUTPUT.PUT_LINE('Something wrong in the formula!');
END IF;
IF emp_c_v.v_commission_pct IS NULL
THEN
DBMS_OUTPUT.PUT_LINE('No Commission added to the annual salary!');
ELSE
DBMS_OUTPUT.PUT_LINE('Commission percentage to the salary is:-> '|| emp_c_v.v_commission_pct ||'%');
emp_c_v.v_comm_calc := (emp_c_v.v_annual_sal * emp_c_v.v_commission_pct) + emp_c_v.v_annual_sal;
DBMS_OUTPUT.PUT_LINE('And calculated with annual salary is:->' ||v_comm_calc);
END IF;
DBMS_OUTPUT.PUT_LINE('Working for:-> '|| emp_c_v.v_tenure || ' months as '|| emp_c_v.v_job_id);
DBMS_OUTPUT.PUT_LINE('=============================');
DBMS_OUTPUT.PUT_LINE('Started in:-> '|| emp_c_v.v_hire_date);
DBMS_OUTPUT.PUT_LINE('=============================');
DBMS_OUTPUT.PUT_LINE('Phone number:-> '||emp_c_v.v_phone_number);
DBMS_OUTPUT.PUT_LINE('=============================');
DBMS_OUTPUT.PUT_LINE('Email:-> '||emp_c_v.v_email);
DBMS_OUTPUT.PUT_LINE('=============================');
OPEN c_city;
FETCH c_city INTO v_city;
IF c_city%FOUND
THEN
DBMS_OUTPUT.PUT_LINE('Location:-> '||emp_c_v.v_city);
ELSE
DBMS_OUTPUT.PUT_LINE('Employee location unknown');
END IF;
CLOSE c_city;
OPEN c_manager;
FETCH c_manager INTO emp_c_v.v_manager;
IF c_manager%FOUND
THEN
DBMS_OUTPUT.PUT_LINE('Is in the eyes of manager:-> '||emp_c_v.v_manager);
ELSE
DBMS_OUTPUT.PUT_LINE('Slave '||emp_c_v.v_last_name||' is free!');
END IF;
CLOSE c_manager;
OPEN c_department_name;
FETCH c_department_name INTO emp_c_v.v_department;
IF c_department_name%FOUND
THEN
DBMS_OUTPUT.PUT_LINE('Department Name:-> '||emp_c_v.v_department);
ELSE
DBMS_OUTPUT.PUT_LINE('Employee ' ||emp_c_v.v_last_name||' belongs to no department!');
END IF;
DBMS_OUTPUT.PUT_LINE('================================');
DBMS_OUTPUT.PUT_LINE('Checking for employee with id '|| p_id ||'..');
IF (check_sal2(p_id) IS NULL)
THEN
DBMS_OUTPUT.PUT_LINE('The function returned NULL due to exception, therefore employee does not exist!');
ELSIF (check_sal2(p_id))
THEN
DBMS_OUTPUT.PUT_LINE('Employees salary > average of department '||emp_c_v.v_deptno||' where he belongs.');
ELSE
DBMS_OUTPUT.PUT_LINE('Salary < average of department '||emp_c_v.v_deptno||', where he belongs.');
END IF;
DBMS_OUTPUT.PUT_LINE('=====================================================');
END;
Initially i had only simple variables (v_...) declared in this sub-program but i wanted to make use of true cursor variables i.e like-pointers? i suppose. So i modified and defined a type of record and referenced a cursor "...IS REF CURSOR" for the variables or fields inside it. But when i compile this whole thing i get the error of invalid reference to variable "emp_c_v", why? I am still in the learning stages so sorry for talking nonsense. Thanks

Answer 1

A cursor is a pointer to a result set (sort of), not to an individual record. You can't ever modify a result set. In this case the pointer wouldn't actually point to anything as there isn't a result set (from a query) for it to point to.
Your code will almost compile if you drop the ref cursor and make your variable a record type; so instead of:
TYPE EmpCurTyp IS REF CURSOR;
emp_c_v EmpCurTyp;
use:
emp_c_v EmpRecTyp;
You've also missed a couple of places when changing your references:
DBMS_OUTPUT.PUT_LINE('And calculated with annual salary is:->' ||v_comm_calc);
and
FETCH c_city INTO v_city;
... both need the emp_c_v. prefix before v_comm_calc and v_city respectively.
I assume you're using this as a learning exercise, otherwise this could all be done much more simply.