ORA-00932: inconsistent datatypes: expected - got -

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 tim

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.