存储过程,作用域

drop procedure if exists p11;delimiter // create procedure p11 ()  begin    declare x1 char(5) default 'outer';    begin      declare x1 char(5) default 'inner';      select x1;      end;    select x1;  end; //   delimiter ;call p11();/*+-------+| x1    |+-------+| inner |+-------+1 row in set (0.00 sec)+-------+| x1    |+-------+| outer |+-------+1 row in set (0.01 sec)*/