Oracle跳过了嵌套的PIPELINED函数

Question

I'll post a trivial example, which actually works, just to get an approximate picture of what I'm trying to achieve:

Here is the 'inner' function which takes the data from some table, called test_tab :

create or replace function test_inner RETURN num_typ PIPELINED
IS
BEGIN
  FOR cur in (
    SELECT x FROM test_tab
  )
  LOOP
    PIPE ROW(cur.x);
  END LOOP;
END;
/

Here is the 'outer' function which uses the result of inner function and transforms them appropriately:

create or replace function test_outer RETURN num_typ PIPELINED
IS
BEGIN
  FOR x IN (
    SELECT * FROM table(test_inner())
  )
  LOOP
    PIPE ROW(x.column_value * 2);
  END LOOP;
END;
/

And here is how I use it:

begin
  execute immediate 'insert into test_tab(x) values(1)';
  execute immediate 'insert into test_tab(x) values(2)';
  execute immediate 'insert into test_tab(x) values(3)';

  FOR x IN (
    select * from table(test_outer())
  ) LOOP  
    DBMS_OUTPUT.put_line(x.column_value);
  END LOOP;  
end;
/

The problem is that test_inner function seems to be ignored by Oracle. When it is called separately, it 'sees' the data inserted prior to its execution. But when it's called as a part of test_outer it doesn't return any data, or maybe doesn't get called at all.

Like I said, the above example will work. But my case is a little bit more complex, so I can't post it entirely.

Answer 1

The test case you have posted does not reproduce the problem you claim to be seeing. So it is not a test case.

@AlexPoole has provided you with some other ideas. Basically there is nothing further we can do unless you can post a better test case, given that you cannot post the entire things (and we don't want to go through hundreds of lines of somebody else's shonky code - I for one get enough of that debugging my own stuff).

Producing a poor test case has not been a waste of time. At least you can rule out certain things: it's nothing to do with one pipelined function calling another. So it's clearly something in your specific implementation. Perhaps not in the internal function logic, but how they are called, the data they work with or some other part of the infrastructure.

All you can do is analyse the individual parts. Start with the core component, and build out, adding other components until you find the bit which breaks. Yes this is a tedious chore. But from your comments it sounds like you're quite a way through this process already.

---

I'm marking this CW as it isn't an answer to the question, just an extended comment.

Answer 2

Your both pipelined functions in fact are syntactic wrong: you are missing RETURN

See docs