mysql存储过程的优缺点

DELIMITER //

CREATE PROCEDURE ordertotal(

IN custid INT,

IN taxable BOOLEAN,

OUT ototal DECIMAL(8,2)

)COMMENT 'obtain total order price'

BEGIN

/*declare variable for total*/

DECLARE total DECIMAL(8,2);

DECLARE taxrate INT DEFAULT 6;

/*get the order total*/

SELECT SUM(item_price*item_quantity) INTO total

FROM customers

WHERE cust_id = custid;

/*is this taxable?*/

IF taxable THEN

 SELECT total+(total/100*taxrate) INTO total;

END IF;

SELECT total INTO ototal;

END //