How do I retrieve values from a nested Oracle procedure? - oracle

Question

I have kind of a tricky Oracle problem. I am trying to select one set of data, we'll call items. For each item I want to call another procedure and return an Inventory Item. I have two operations I am not sure on how to perform.
How do I retrieve a value from the nested procedure?
How do I return those retrieved values in the form of SYS_REFCURSOR?
My attempt here was to put the results from spSelect_Inv_Search into a nested table called ITEMS_TABLE. This is not working.
Code below
PROCEDURE SPSELECT_ITEM (IO_CURSOR OUT SYS_REFCURSOR)
AS
MY_CURSOR SYS_REFCURSOR;
TYPE ITEM_TYPE IS TABLE OF ITEMS.ITEM_NO%TYPE;
ITEM_TABLE ITEM_TYPE := ITEM_TYPE();
CURSOR ITEMS_CURSOR IS
SELECT ITEM_NO
FROM ITEMS;
V_COUNTER INTEGER := 0;
BEGIN
FOR ITEM_REC IN ITEM_CURSOR LOOP
V_COUNTER := V_COUNTER + 1;
ITEM_TABLE.EXTEND;
ITEM_TABLE(V_COUNTER) := spSelect_Inv_Search(ITEM_REC.ITEM_NO, MY_CURSOR);
END LOOP;
END SPSELECT_ITEMS;
Any help is appreciated, thanks.

Answer 1

You seem to be wanting to merge an unknown number of SYS_REFCURSOR result sets into one big one. If you know the structure of the cursor returned from spSelect_Inv_Search you can do this with an intermediate pipelined function.
create package p as
type tmp_rec_type is record (owner all_objects.owner%type,
object_type all_objects.object_type%type,
objects number);
type tmp_rec_table is table of tmp_rec_type;
procedure proc1(p_owner in varchar2, p_cursor out sys_refcursor);
function func2 return tmp_rec_table pipelined;
procedure proc3(p_cursor out sys_refcursor);
end;
/
The types can be defined here, they don't have to be at SQL level as you won't ever need to reference them outside the package.
create package body p as
procedure proc1(p_owner in varchar2, p_cursor out sys_refcursor) as
begin
open p_cursor for select owner, object_type, count(*)
from all_objects
where owner = p_owner
group by owner, object_type;
end;
function func2 return tmp_rec_table pipelined as
cursor c1 is select distinct owner
from all_tables where owner in ('SYS','SYSTEM');
tmp_cursor sys_refcursor;
tmp_rec tmp_rec_type;
begin
for r1 in c1 loop
proc1(r1.owner, tmp_cursor);
loop
fetch tmp_cursor into tmp_rec;
exit when tmp_cursor%notfound;
pipe row(tmp_rec);
end loop;
end loop;
end;
procedure proc3(p_cursor out sys_refcursor) as
begin
open p_cursor for select * from table(func2);
end;
end p;
/
Then to execute, which you can do outside the package despite the types used for the intermediate stage, you can do this to test in SQL*Plus or SQL Developer:
var rc refcursor;
exec p.proc3(:rc);
print rc;
For my database this gives:
OWNER OBJECT_TYPE OBJECTS
------------------------------ ------------------- ----------------------
SYSTEM VIEW 1
SYSTEM TABLE 5
SYS VIEW 1056
SYS CONSUMER GROUP 2
SYS PROCEDURE 11
SYS FUNCTION 56
SYS SEQUENCE 1
SYS OPERATOR 6
SYS EVALUATION CONTEXT 1
SYS TABLE 13
SYS WINDOW GROUP 1
SYS PACKAGE 162
SYS WINDOW 2
SYS TYPE 529
SYS JOB CLASS 1
SYS SCHEDULE 1
This is obviously very contrived as you'd do this as a single query, but I'm assuming your inner procedure needs to do something more complicated.

Answer 2

In to answer your question about how to call spSelect_Inv_Search, I'd need to know the signature of that subprogram. You've described it as a procedure but you're trying to call it as a function. Which is it? What return value and/or OUT-mode parameters does it have?
To return an open REF CURSOR from the above procedure, first the nested table type needs to be declared at the schema level (using a CREATE TYPE statement) instead of in the PL/SQL code. Then you can open the cursor like so, after populating the nested table.
OPEN io_cursor FOR SELECT * FROM TABLE(CAST(item_table AS item_type));
(And by the way, I would change the name of the type from ITEM_TYPE to ITEM_TABLE_TYPE, myself.)