Function to return COUNT value without COUNT - sql

Question

The requirements are as follows:
Create a PL/SQL function called findtotalcarmodels to return the total number of cars belonging to a particular model. The function should have a single IN parameter as model_name. You should then use an explicit cursor to count the number of cars belonging to that car model and return the final count. You must NOT use any implicit cursors, table joins, subqueries, set operators, group functions or SQL functions (such as COUNT) to create this function.
The code I have come up with so far is:
CREATE OR REPLACE Function findtotalcarmodels
(model_name IN varchar2)
RETURN NUMBER
IS
CURSOR car_count_cur IS
SELECT model_name FROM i_car;
Rec_car_details car_count_cur%ROWTYPE;
BEGIN
OPEN car_count_cur;
LOOP
FETCH car_count_cur INTO Rec_car_details;
EXIT WHEN car_count_cur%NOTFOUND;
END LOOP;
CLOSE car_count_cur;
RETURN Rec_car_details;
END;
I am getting the following errors:
Errors for FUNCTION FINDTOTALCARMODELS:
LINE/COL ERROR
15/1 PL/SQL: Statement ignored
15/8 PLS-00382: expression is of wrong type
What am I doing wrong here?

Answer 1

You are trying to return the cursor from the inline function, and the function is looking to return an integer.
You need an (integer) counter to increment each time you iterate through the cursor... and then you can return that. I didn't test this, but this should work:
CREATE OR REPLACE Function findtotalcarmodels
(model_name_in IN varchar2)
RETURN NUMBER
IS
DECLARE counter INTEGER := 0;
CURSOR car_count_cur IS
SELECT model_name FROM i_car WHERE model_name = model_name_in;
Rec_car_details car_count_cur%ROWTYPE;
BEGIN
OPEN car_count_cur;
LOOP
FETCH car_count_cur INTO Rec_car_details;
EXIT WHEN car_count_cur%NOTFOUND;
counter := counter + 1;
END LOOP;
CLOSE car_count_cur;
RETURN counter;
END;

Answer 2

CREATE OR REPLACE FUNCTION findtotalcarmodels (vc_model_name IN VARCHAR2)
RETURN NUMBER
AS
CURSOR c1
IS
SELECT *
FROM i_car
WHERE UPPER (model_name) = UPPER (vc_model_name);
cnt NUMBER;
BEGIN
cnt := 0;
FOR i IN c1 LOOP
cnt := cnt + 1;
END LOOP;
RETURN cnt;
END;
You can check in dual table such as,
SELECT findtotalcarmodels('SUV1') FROM DUAL; -- here suv1 is your modelname