ORA-00932: inconsistent datatypes: expected - got - - oracle

Question

I have been using Oracle(10g.2) as a PHP programmer for almost 3 years, but when I gave an assignment, I have tried to use the ref cursors and collection types for the first time. And I
've searched the web, when I faced with problems, and this ora-00932 error really overwhelmed me. I need help from an old hand.
Here is what I've been tackling with,
I want to select rows from a table and put them in a ref cursor, and then with using record type, gather them within an associative array. And again from this associative array, make a ref cursor. Don't ask me why, I am writing such a complicated code, because I need it for more complex assignment. I might be sound confusing to you, thus let me show you my codes.
I have 2 types defined under the types tab in Toad. One of them is an object type:
CREATE OR REPLACE
TYPE R_TYPE AS OBJECT(sqn number,firstname VARCHAR2(30), lastname VARCHAR2(30));
Other one is collection type which is using the object type created above:
CREATE OR REPLACE
TYPE tr_type AS TABLE OF r_type;
Then I create a package:
CREATE OR REPLACE PACKAGE MYPACK_PKG IS
TYPE MY_REF_CURSOR IS REF CURSOR;
PROCEDURE MY_PROC(r_cursor OUT MY_REF_CURSOR);
END MYPACK_PKG;
Package Body:
CREATE OR REPLACE PACKAGE BODY MYPACK_PKG AS
PROCEDURE MY_PROC(r_cursor OUT MY_REF_CURSOR) AS
rcur MYPACK_PKG.MY_REF_CURSOR;
sql_stmt VARCHAR2(1000);
l_rarray tr_type := tr_type();
l_rec r_type;
BEGIN
sql_stmt := 'SELECT 1,e.first_name,e.last_name FROM hr.employees e ';
OPEN rcur FOR sql_stmt;
LOOP
fetch rcur into l_rec;
exit when rcur%notfound;
l_rarray := tr_type( l_rec );
END LOOP;
CLOSE rcur;
--OPEN r_cursor FOR SELECT * FROM TABLE(cast(l_rarray as tr_type) );
END MY_PROC;
END MYPACK_PKG;
I commented out the last line where I open ref cursor. Because it's causing another error when I run the procedure in Toad's SQL Editor, and it is the second question that I will ask.
And lastly I run the code in Toad:
variable r refcursor
declare
r_out MYPACK_PKG.MY_REF_CURSOR;
begin
MYPACK_PKG.MY_PROC(r_out);
:r := r_out;
end;
print :r
There I get the ora-00932 error.

Answer 1

The way you are using the REF CURSOR is uncommon. This would be the standard way of using them:
SQL> CREATE OR REPLACE PACKAGE BODY MYPACK_PKG AS
2 PROCEDURE MY_PROC(r_cursor OUT MY_REF_CURSOR) AS
3 BEGIN
4 OPEN r_cursor FOR SELECT e.empno,e.ENAME,null FROM scott.emp e;
5 END MY_PROC;
6 END MYPACK_PKG;
7 /
Corps de package crÚÚ.
SQL> VARIABLE r REFCURSOR
SQL> BEGIN
2 MYPACK_PKG.MY_PROC(:r);
3 END;
4 /
ProcÚdure PL/SQL terminÚe avec succÞs.
SQL> PRINT :r
EMPNO ENAME N
---------- ---------- -
7369 SMITH
7499 ALLEN
7521 WARD
7566 JONES
7654 MARTIN
[...]
14 ligne(s) sÚlectionnÚe(s).
I'm not sure what you are trying to accomplish here, you're fetching the ref cursor inside the procedure and then returning another ref cursor that will have the same data. I don't think it's necessary to fetch the cursor at all in the procedure. Let the calling app do the fetching (here the fetching is done by the print).
Update: why are you getting the unhelpful error message?
You're using a cursor opened dynamically and I think that's part of the reason you are getting the unhelpful error message. If we use fixed SQL the error message is different:
SQL> CREATE OR REPLACE PACKAGE BODY MYPACK_PKG AS
2 PROCEDURE MY_PROC(r_cursor OUT MY_REF_CURSOR) AS
3 TYPE type_rec IS RECORD (qn number,
4 firstname VARCHAR2(30),
5 lastname VARCHAR2(30));
6 lt_record type_rec; /* Record type */
7 lt_object r_type; /* SQL Object type */
8 BEGIN
9 OPEN r_cursor FOR SELECT e.empno,e.ENAME,null FROM scott.emp e;
10 FETCH r_cursor INTO lt_record; /* This will work */
11 FETCH r_cursor INTO lt_object; /* This won't work in 10.2 */
12 END MY_PROC;
13 END MYPACK_PKG;
14 /
Package body created
SQL> VARIABLE r REFCURSOR
SQL> BEGIN
2 MYPACK_PKG.MY_PROC(:r);
3 END;
4 /
BEGIN
*
ERREUR Ó la ligne 1 :
ORA-06504: PL/SQL: Return types of Result Set variables or query do not match
ORA-06512: at "APPS.MYPACK_PKG", line 11
ORA-06512: at line 2
I outlined that currently in 10.2 you can fetch a cursor into a PLSQL record but not in a SQL Object.
Update: regarding the PLS-00306: wrong number or types of arguments
l_rarray is a NESTED TABLE, it needs to be initialized and then extended to be able to store elements. For example:
SQL> CREATE OR REPLACE PACKAGE BODY MYPACK_PKG AS
2 PROCEDURE MY_PROC(r_cursor OUT MY_REF_CURSOR) AS
3 lr_array tr_type := tr_type(); /* SQL Array */
4 BEGIN
5 FOR cc IN (SELECT e.empno, e.ENAME, NULL lastname
6 FROM scott.emp e) LOOP
7 lr_array.extend;
8 lr_array(lr_array.count) := r_type(cc.empno,
9 cc.ename,
10 cc.lastname);
11 /* Here you can do additional procedural work on lr_array */
12 END LOOP;
13 /* then return the result set */
14 OPEN r_cursor FOR SELECT * FROM TABLE (lr_array);
15 END MY_PROC;
16 END MYPACK_PKG;
17 /
Corps de package crÚÚ.
SQL> print r
SQN FIRSTNAME LASTNAME
---------- ------------------------------ -----------
7369 SMITH
7499 ALLEN
7521 WARD
[...]
14 ligne(s) sÚlectionnÚe(s).
For further reading you can browse the documentation for PL/SQL collections and records.