sdasd

create PROCEDURE v4(in c_year int)
BEGIN
	declare num int(10) default 0;
	declare num1 int(10);
			select code into num from class where class=c_year order by code desc limit 1;

		IF exists(select * from class where class=c_year) THEN

				    insert into class(class,code)values(c_year,num+1);
		else
				insert into class(class,code)values(c_year,1);
	end if;			

end;

　　

BEGIN
 DECLARE a_class VARCHAR (10);
 DECLARE a_code int (10);
 DECLARE a_int INT (10);
SELECT IFNULL(class, class) INTO a_class;
select SUBSTR('0000',4,4)+'0' into a_code;
select a_int=a_code+1;
IF class = a_class THEN
  IF a_int<10  THEN
			insert into class(class,code)VALUES(a_class,CONCAT(a_class,'000',a_int));
	elseIF a_int <100 THEN
			insert into class(class,code)VALUES(a_class,CONCAT(a_class,'00',a_int));
	elseIF a_int <1000 THEN
			insert into class(class,code)VALUES(a_class,CONCAT(a_class,'0',a_int));
	elseif a_int<10000 THEN
			insert into class(class,code)VALUE(a_class,concat(a_class,a_int));
end if;
end if;
set  a_int=a_code+1;
end

　　

create PROCEDURE class_a(in c_year int)
begin
  declare num int;
      if exists(select * from class where class=c_year) then
        update class set code=code+1 where class=c_year;
      else
        insert into class(class,code)values(c_year,1);
      end if;
  select code into num from class where class=c_year;
  select CONCAT(c_year, lpad(num,4,0)) as code_a;

  end;