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;