mysql create function
-- MySQL
-- example
DELIMITER $$
CREATE FUNCTION f_employee_count(p_dept_no INTEGER) RETURNS INTEGER
DETERMINISTIC NO SQL READS SQL DATA
BEGIN
DECLARE v_emp_count INTEGER;
SELECT COUNT(*)
INTO v_emp_count
FROM EMPLOYEES E
WHERE E.DEPT_NO = p_dept_no
GROUP BY DEPARTMENT_NO;
RETURN v_emp_count;
END$$
DELIMITER ;
/* syntax:
DELIMITER $$
CREATE FUNCTION <Your-procedure-name>(<arguments>) RETURNS <date-type>
DETERMINISTIC NO SQL READS SQL DATA
BEGIN
DECLARE <variable-name> <data-type>
<Code-that-sets-the-output-variable>;
RETURN <variable-name>;
END$$
DELIMITER ;
*/