DELIMITER //
DROP PROCEDURE IF EXISTS `test`.`p_getvalue` //
CREATE DEFINER=`root`@`localhost` PROCEDURE `p_getvalue`(
in id varchar(20),out s varchar(20)
)
begin
if (length(id)=11) then select 'A_B_C_D' into s;
elseif(length(id)=8) then select 'A_B_C' into s;
elseif(length(id)=5) then select 'A_B' into s;
elseif(length(id)=2) then select 'A' into s;
end if;
select s;
end //
DELIMITER ;

CALL p_getvalue('11000112',@S)