Function returning a set of records - how to do this?

Question

Hi,
I need to return something of a table as a result:
function Find_Item (vNUMBER in NUMBER(3,0)
vNAME in VARCHAR2(200) ) return ???
as
begin
SELECT UUID, Number, Name FROM Tab1
Where NUMBER LIKE vNUMBER|| '%'
intersect
SELECT UUID, Number, Name FROM Tab1
Where NAME LIKE vNAME|| '%' ;
end;
How to do this? Should I use a collection? Any ideas? I would be grateful for any hint.
Best regards,
Alicja

Answer 1

user651039 wrote:
And it would work if not for INTERSECT. So, I either I change the query or have to find walk-around.What is the issue with the INTERSECT? Why should the approach shown not work when using INTERSECT?
Note that you can't define the parameters of your function like that, you have to specify the length of the varchar2 column in the calling code.
If your query is going to return potentially a large number of rows you should consider using a "pipelined" function, as already mentioned, as the non-pipelined version could be consuming a lot of memory in case a large collection is going to be generated.
Here's a sample of a pipelined table function:
alter session set nls_language = 'AMERICAN';
set echo on linesize 130 feedback 1
drop type t_find_item_record_col force;
drop type t_find_item_record force;
drop function find_item;
create or replace type t_find_item_record as object(
uuid varchar2(30),
a_number number,
a_name varchar2(30)
create or replace type t_find_item_record_col as table of t_find_item_record;
create or replace function find_item(
vNUMBER in NUMBER, vNAME in VARCHAR2) return t_find_item_record_col pipelined
as
  a_find_item_record_col t_find_item_record_col;
  cursor c is
  select t_find_item_record(uuid, a_number, a_name) from (
  SELECT cast('a' as varchar2(30)) as UUID, 1 as a_Number, cast('b' as varchar2(30)) as a_Name
  FROM dual
  Where 35 LIKE vNUMBER|| '%'
  intersect
  SELECT 'a' as UUID, 1 as a_Number, 'b' a_Name FROM dual
  Where 'Bob' LIKE vNAME|| '%'
begin
  open c;
  loop
    fetch c bulk collect into a_find_item_record_col limit 100;
    for i in 1..a_find_item_record_col.count loop
      pipe row(a_find_item_record_col(i));
    end loop;
    exit when a_find_item_record_col.count = 0;
  end loop;
  close c;
  return;
end;
select * from table(find_item(35, 'Bob'));Another option you might want to consider is using a REF CURSOR return type, so that you open the cursor accordingly in your function and return the opened cursor to the caller. The caller can then fetch from this cursor.
And here's a sample function using ref cursor:
create or replace function find_item_cursor(
vNUMBER in NUMBER, vNAME in VARCHAR2) return sys_refcursor
as
  c sys_refcursor;
begin
  open c for
  SELECT cast('a' as varchar2(30)) as UUID, 1 as a_Number, cast('b' as varchar2(30)) as a_Name
  FROM dual
  Where 35 LIKE vNUMBER|| '%'
  intersect
  SELECT 'a' as UUID, 1 as a_Number, 'b' a_Name FROM dual
  Where 'Bob' LIKE vNAME|| '%';
  return c;
end;
variable a refcursor
exec :a := find_item_cursor(35, 'Bob')
print aHere's the output of the samples:
Session altered.
SQL>
SQL> drop type t_find_item_record_col force;
Type dropped.
SQL>
SQL> drop type t_find_item_record force;
Type dropped.
SQL>
SQL> drop function find_item;
Function dropped.
SQL>
SQL> create or replace type t_find_item_record as object(
  2  uuid varchar2(30),
  3  a_number number,
  4  a_name varchar2(30)
  5  );
  6  /
Type created.
SQL>
SQL> create or replace type t_find_item_record_col as table of t_find_item_recor
d;
  2  /
Type created.
SQL>
SQL>
SQL> create or replace function find_item(
  2  vNUMBER in NUMBER, vNAME in VARCHAR2) return t_find_item_record_col pipelin
ed
  3  as
  4    a_find_item_record_col t_find_item_record_col;
  5    cursor c is
  6    select t_find_item_record(uuid, a_number, a_name) from (
  7    SELECT cast('a' as varchar2(30)) as UUID, 1 as a_Number, cast('b' as varc
har2(30)) as a_Name
  8    FROM dual
  9    Where 35 LIKE vNUMBER|| '%'
10    intersect
11    SELECT 'a' as UUID, 1 as a_Number, 'b' a_Name FROM dual
12    Where 'Bob' LIKE vNAME|| '%'
13    );
14  begin
15    open c;
16    loop
17      fetch c bulk collect into a_find_item_record_col limit 100;
18      for i in 1..a_find_item_record_col.count loop
19        pipe row(a_find_item_record_col(i));
20      end loop;
21      exit when a_find_item_record_col.count = 0;
22    end loop;
23    close c;
24    return;
25  end;
26  /
Function created.
SQL>
SQL> select * from table(find_item(35, 'Bob'));
UUID                             A_NUMBER A_NAME
a                                       1 b
1 row selected.
SQL>
SQL> create or replace function find_item_cursor(
  2  vNUMBER in NUMBER, vNAME in VARCHAR2) return sys_refcursor
  3  as
  4    c sys_refcursor;
  5  begin
  6    open c for
  7    SELECT cast('a' as varchar2(30)) as UUID, 1 as a_Number, cast('b' as varc
har2(30)) as a_Name
  8    FROM dual
  9    Where 35 LIKE vNUMBER|| '%'
10    intersect
11    SELECT 'a' as UUID, 1 as a_Number, 'b' a_Name FROM dual
12    Where 'Bob' LIKE vNAME|| '%';
13    return c;
14  end;
15  /
Function created.
SQL>
SQL> variable a refcursor
SQL>
SQL> exec :a := find_item_cursor(35, 'Bob')
PL/SQL procedure successfully completed.
SQL>
SQL> print a
UUID                             A_NUMBER A_NAME
a                                       1 b
1 row selected.Regards,
Randolf
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