Table-Valued Functions in ORACLE 11g ? ( parameterized views )

eidylon picture eidylon · Jan 13, 2010 · Viewed 25.6k times · Source

I've seen discussions about this in the past, such as here. But I'm wondering if somewhere along the line, maybe 10g or 11g (we are using 11g), ORACLE has introduced any better support for "parameterized views", without needing to litter the database with all sorts of user-defined types and/or cursor definitions or sys_context variables all over.

I'm hoping maybe ORACLE's added support for something that simply "just works", as per the following example in T-SQL:

CREATE FUNCTION [dbo].[getSomeData] (@PRODID ROWID)  
RETURNS TABLE AS  
    RETURN SELECT PRODID, A, B, C, D, E  
    FROM MY_TABLE  
    WHERE PRODID = @PRODID

Then just selecting it as so:

SELECT * FROM dbo.getSomeData(23)

Answer

Gary Myers picture Gary Myers · Jan 13, 2010

No need for SYS_CONTEXT or cursor definitions. You do need a type so that, when the SQL is parsed, it can determine which columns are going to be returned. That said, you can easily write a script that will generate type and collection type definitions for one or more tables based on the data in user_tab_columns.

The closest is

create table my_table
(prodid number, a varchar2(1), b varchar2(1), 
  c varchar2(1), d varchar2(1), e varchar2(1));

create type my_tab_type is object
(prodid number, a varchar2(1), b varchar2(1), 
  c varchar2(1), d varchar2(1), e varchar2(1))
.
/

create type my_tab_type_coll is table of my_tab_type;
/

create or replace function get_some_data (p_val in number) 
return my_tab_type_coll pipelined is
begin
  FOR i in (select * from my_table where prodid=p_val) loop
    pipe row(my_tab_type(i.prodid,i.a,i.b,i.c,i.d,i.e));
  end loop;
  return;
end;
/

SELECT * FROM table(get_Some_Data(3));