问题
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?
回答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>
回答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
回答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.
来源：https://stackoverflow.com/questions/4614475/how-to-call-a-function-in-a-package