ORA-00932: inconsistent datatypes: expected - got -

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.

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.