%type变量：用户事先并不清楚检索的数据列的数据类型，则可以使用%type定义变量
declare
name student.sname %type；
no student.sno %type；
begin
select sno,sname into no,name from student where sno="soo1"
dbms_output.putline(name || '' ||no);
end;
%rowtype
delare
id student%rowtype;
begin
select * into id from student where sn0 ="s001";
dbms_output.put_line(id.name ||''||id.sage)
end;