新手上路，这个错误是什么意思呢，求解！

Question

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1

Answer 1

create trigger t4
before
insert
on ord
for each row
begin
    declare has_num int;
    select good_num into has_num from good where good_id = new.good_id;
    
    if has_num < new.ord_num then

    set new.ord_num = has_num;

    end if;

    update good set good_num =0 where good_id = new.good_id;   

end$