mysql 自定义函数一直报错语法有问题，找不哪里错了，求大神帮忙 ?报错

函数代码如下：
问题：
1.保存是报错变量申明有问题（其他函数这样申明变量没出过问题），

    2. 当把报错的变量申明删掉之后又会，又会报其他语句错误（这语句单独提出来运行是没问题的）
    ![图片说明](https://img-ask.csdn.net/upload/201811/20/1542678225_736322.png)







    我觉应该可能不是那个语句的问题，第一写sql函数的没有定义函数类型，一直报错某个句子语法有问题，当我定义了类函数类型（之前报错这个句子没有做任何修改）之后就没问题










    CREATE DEFINER=`root`@`localhost` FUNCTION `etccalcute`(`date_start` datetime,`date_end` datetime,car_id varchar(7)) RETURNS double
MODIFIES SQL DATA

BEGIN
declare etc_sum double;
declare dis_sum double;
declare detc double(3,2)；
declare date_s datetime;
declare date_e datatime;
declare n int;
declare m int;

truncate table etc_base;

insert into etc_base(date_delivery_required,project,distance_real)  select date_delivery_required，project，distance_real from orders 
 where date_delivery_required between date_start and date_end
 and car_number=car_id order by date_delivery_required asc;  

 select count(distinct precject) from etc_base into n;

if(n=1)
    begin
             select max(id) from etc_base into m;

                 select date_delivery_required from etc_base where id=1 into date_s;
                 select date_delivery_required from etc_base where id=m-1 into date_e;

                select sum(consumpation_amount) from etc
                where consumpation_time between date_s and date_e
                and car=car_id into etc_sum;

                select sum(distance_real) from etc_base
                where id between 1 and m-1 into dis_sum;

                set detc=etc_sum/dis_sum;
                RETURN detc;
    end
else
  BEGIN
        RETURN -1   
 END    

END;