--你想用 table() 这种方式查询数据，你的函数不能是普通函数。
create table tb1(k number, v varchar2(10)); 

insert into tb1(k, v) values(100,'aaa'); 
insert into tb1(k, v) values(200,'bbb'); 
insert into tb1(k, v) values(200,'ccc'); 

select * from tb1; 

create type row_type1 as object(k number, v varchar2(10)); 

create type table_type1 as table of row_type1; 

create or replace function fun1 return table_type1 pipelined as 
v row_type1; 
begin 
     for myrow in (select k, v from tb1) loop 
       v := row_type1(myrow.k, myrow.v); 
       pipe row (v); 
     end loop; 
     return; 
end; 

select * from table(fun1);