如何在mysql中使用diffdate函數使用變量

Question

CREATE DEFINER=`root`@`localhost` PROCEDURE `bill`(subid int(10), uprice float, sd date, ed date) 
BEGIN 
declare numberofdays int; 
declare totalprice float; 

set numberofdays = datediff(ed,sd); 
set totalprice= numberofdays*uprice; 

insert into invoice (subscriptionid,price_perunit,numberofdays,totalprice) 
values (subid, uprice,numberofdays,totalprice); 

Answer 1

你的代碼（語法）是正確的。您可能在變量和字段名稱方面存在問題，請嘗試使用不同的名稱，例如 -

CREATE DEFINER = root@localhost PROCEDURE bill (subid int(10), uprice float, sd date, ed date) 
BEGIN 
    DECLARE var_numberofdays int; 
    DECLARE var_totalprice float; 

    SET var_numberofdays = DATEDIFF(ed, sd); 
    SET var_totalprice = var_numberofdays * uprice; 

    INSERT INTO invoice (subscriptionid, price_perunit, numberofdays, totalprice) 
    VALUES (subid, uprice, var_numberofdays, var_totalprice); 

    ... 
END;