Mysql Decimal division automatically round up - mysql

Question

My Function is
DELIMITER $$;
CREATE FUNCTION get_approved_leaves(f_date date, t_date date,
emp_id bigint, ltp_id int)
RETURNS INT NOT DETERMINISTIC
BEGIN
DECLARE leaves_taken decimal(10,3) DEFAULT 0.000;
SELECT SUM(eld_first+eld_second)/2
INTO leaves_taken
FROM erp_apply_leaves, erp_employee_leave_debts
WHERE al_fk_employees = emp_id
AND al_from >= f_date
AND al_to <= t_date
AND al_fk_leave_type = ltp_id
AND eld_fk_apply_leaves = al_id
AND al_status = 101;
RETURN leaves_taken;
END $$;
DELIMITER ;
When I call
SELECT get_approved_leaves('2017-01-01','2017-12-31',18, 5) as debted
FROM `erp_employee_leave_debts` WHERE 1
It gives the out put : 20
But here SUM(eld_first+eld_second) = 39. So I need to get the output = 19.5

Answer 1

Your function definition is expecting an INT as return value.
And as you are returning leaves_taken value, which is of type DECIMAL(10,3),
SQL Engine is converting it to nearest INTEGER value, to match the return type, and returning.
If you want to keep the original value, better you change the return type of the function.
Example is given below:
CREATE FUNCTION
get_approved_leaves( f_date date, t_date date
, emp_id bigint, ltp_id int )
RETURNS DECIMAL(10,3) NOT DETERMINISTIC