How to call a function in a package - sql

Question

I'm doing the following but it doesnt work
select package_name.function_name(param,param) from dual
I'm calling a function that returns a cursor so im guessing "from dual" is the problem
is there another way of doing it?

Answer 1

I presume you mean a Ref Cursor. This is a PL/SQL construct which acts as a pointer to a set of records returned by a query. This means it has to be interpreted by the client which runs the query. For instance, we can map a Ref Cursor to a JDBC or ODBC ResultSet.
There is certainly nothing wrong with your basic statement. Here is a function similar to your own:
SQL> desc get_emps
FUNCTION get_emps RETURNS REF CURSOR
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
P_DNO NUMBER(2) IN
P_SORT_COL VARCHAR2 IN DEFAULT
P_ASC_DESC VARCHAR2 IN DEFAULT
SQL>
I can easily call this in a wider PL/SQL block:
SQL> declare
2 rc sys_refcursor;
3 begin
4 rc := get_emps(50);
5 end;
6 /
PL/SQL procedure successfully completed.
SQL>
However, SQL*PLus can handle CURSOR constructs natively:
SQL> select get_emps(50) from dual
2 /
GET_EMPS(50)
--------------------
CURSOR STATEMENT : 1
CURSOR STATEMENT : 1
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
8060 VERREYNNE PLUMBER 8061 08-APR-08 4000 50
8061 FEUERSTEIN PLUMBER 7839 27-FEB-10 4500 50
8085 TRICHLER PLUMBER 8061 08-APR-10 3500 50
8100 PODER PLUMBER 8061 3750 50
SQL>
This statement also runs in SQL Developer, although the result set is laid out in an ugly fashion.
So, if you are having problems with your function, the questions are:
What client environment are you using?
In what precise fashion does it "not work"? Please describe the observed behaviour, including any error messages?
Also give us environment details such as the version of the database, the OS, etc.
Having read your other question on this topic I thought the problem might be due to the use of a User-Defined Ref Cursor (rather than the built-in). However, that doesn't make any difference. This packaged function:
SQL> create or replace package emp_rc_utils as
2
3 type emp_rc is ref cursor return emp%rowtype;
4
5 function get_emps
6 ( p_dno in emp.deptno%type
7 )
8 return emp_rc;
9 end;
10 /
Package created.
SQL> create or replace package body emp_rc_utils as
2
3 function get_emps
4 ( p_dno in emp.deptno%type
5 )
6 return emp_rc
7 is
8 return_value emp_rc_utils.emp_rc;
9 begin
10
11 open return_value for select * from emp where deptno = p_dno;
12
13 return return_value;
14 end get_emps;
15
16 end emp_rc_utils;
17 /
Package body created.
SQL>
Still works...
SQL> declare
2 rc sys_refcursor;
3 begin
4 rc := emp_rc_utils.get_emps(50);
5 end;
6 /
PL/SQL procedure successfully completed.
SQL> select emp_rc_utils.get_emps(50) from dual
2 /
EMP_RC_UTILS.GET_EMP
--------------------
CURSOR STATEMENT : 1
CURSOR STATEMENT : 1
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
8085 TRICHLER PLUMBER 8061 08-APR-10 3500 50
8060 VERREYNNE PLUMBER 8061 08-APR-08 4000 50
8061 FEUERSTEIN PLUMBER 7839 27-FEB-10 4500 50
8100 PODER PLUMBER 8061 3750 50
SQL>

Answer 2

You can do this via a refcursor call or populate a user defined table and return it as follows:
create or replace
function getRef return sys_refcursor
is
l_ref sys_refcursor;
begin
open l_ref for
select 1 a, 'a' c from dual
union all
select 2 a, 'b' c from dual
union all
select 3 a, 'c' c from dual
union all
select 4 a, 'd' c from dual;
return l_ref;
end getRef;
/
select getref() from dual;
GETREF()
--------
A C
---------------------- -
1 a
2 b
3 c
4 d
--you'll notice this isn't the most user-friendly result set if you look at it in SQL Developer or whatno
--drop function getRef;
you can also use the 'table' if you are passing back a table collection as such
create or replace type lookup_row as
object ( a number, c varchar2(20) );
/
create or replace type lookups_tab as
table of lookup_row;
/
create or replace
function getUserDefinedTableType return lookups_tab
is
lTestTypeTable lookups_tab;
begin
SELECT lookup_row(a,c)
bulk collect INTO lTestTypeTable
from
(select 1 a, 'a' c from dual
union all
select 2 a, 'b' c from dual
union all
select 3 a, 'c' c from dual
union all
select 4 a, 'd' c from dual);
return lTestTypeTable;
end getUserDefinedTableType;
/
select * from table(getUserDefinedTableType());
--this returns it in a more user friendly manner
--http://www.oreillynet.com/pub/a/network/2003/01/22/feuerstein.html?page=2
--http://stackoverflow.com/questions/3150137/converting-oracle-query-into-user-defined-types-in-pl-sql/3152885#3152885
A C
---------------------- --------------------
1 a
2 b
3 c
4 d

Answer 3

have you tried:
myCursor := package_name.function_name(param,param);
this would have to be from within a test block or a stored procedure.