Exception while dequeuing message

Question

Hi,
I am getting an error sayin
"Exception while dequeuing message : Dequeue error in AQ object, ORA-25215: user_
data type and queue type do not match"
What will be the problem?Please help me with solution.
Thanks in advance

Answer 1

This is the link i am following for enqueuing the message into a queue table, its happening successfully.
http://www.oratechinfo.co.uk/aq.html
I can see the message i enqueued in the queue table with the following query at the scheduled time.
select user_data from queue_table;
Below is the C++ code to dequeue the msg.In DequeueObject() function on this particular line "msgid = oaq.Dequeue();"
the control moves to console which not proceeding further.I am wondering what went wrong.
//This is a simple program showing how to call oo4o api from a mulithreaded application.
//Note that every thread has its own OStartup() and OShutdown() routines.
// PROJECT SETTINGS : Under C/C++ option, make sure the project options is /MT for release
// or /MTd for debug(NOT /ML or /MLd).
#include "windows.h"
#include "stdio.h"
#include <iostream>
#include <process.h>          
#include <oracl.h>
using namespace std;
OSession osess ;
int DequeueRaw();
int DequeueObject();
int main(int argc, char **argv)
     int retVal = 0;
     OStartup(OSTARTUP_MULTITHREADED);
     // create session object for each thread. This gives maximum
     // concurrency to the thread execution. This is also useful when OO4O
     // error reported on session object for one thread cannot be seen by
     // another thread.
     try
          osess.Open();
          if ( ! osess.IsOpen() )
               cout << "Session not opened: Error: " << osess.GetErrorText() << endl;
               osess.Close();
               OShutdown();
               return -1;
     //     retVal = DequeueRaw();
          retVal = DequeueObject();
     catch(OException oerr)
          cout << "Exception while dequeuing message : " << oerr.GetErrorText() << endl;
          retVal = -1;
     return retVal;
// This function dequeues a message of default type(string of characters)
// from the raw_msg_queue.
// Gets the message priority after dequeuing
// Checks if any message with correlation like 'AQ' is available on the queue.
int DequeueRaw()
     ODatabase odb;
     OAQ oaq;
     OAQMsg oaqmsg;
     OValue msg;
     const char *msgid = 0;
     odb.Open(osess, "MICROSOFT", "OMNIPOS", "OMNIPOS");
     if ( ! odb.IsOpen() )
          cout << "Database not opened: " << odb.GetErrorText() << endl;
          odb.Close();
          return(-1);
     // Open the 'raw_msg_queue'
     oaq.Open(odb,"example_queue");
     if( !oaq.IsOpen())
          cout << "AQ not opened: " << oaq.GetErrorText() << endl;
          return(-1);
     // Get an instance of the default message(of RAW type)
     oaqmsg.Open(oaq);
     if( !oaqmsg.IsOpen() )
          cout << "AQMsg not opened: " << oaqmsg.GetErrorText() << endl;
          return(-1);
     // Dequeue a message
     //msgid = oaq.Dequeue();
     //if (msgid )
     //     // Retrieve the message attributes
     //     oaqmsg.GetValue(&msg);
     //     const char *msgval = msg;
     //     cout << "Message '" << msgval <<
     //          "' dequeued at priority : " << oaqmsg.GetPriority() << endl;
     // Dequeue message with correlation like "AQ"
     oaq.SetCorrelate("%AQ%");
     oaq.SetDequeueMode(3);
     msgid = oaq.Dequeue();
     if (msgid )
          // Retrieve the message attributes
          char msgval[101];
          long len = oaqmsg.GetValue(msgval,100);
          msgval[len] = '\0';
          cout << "Message '" << msgval <<
               "' dequeued at priority : " << oaqmsg.GetPriority() << endl;
     // Close all of the objects
     oaqmsg.Close();
     oaq.Close();
     odb.Close();
     return 0;
// This function dequeues a message of user-defined type MESSAGE_TYPE
// from the msg_queue.
// Gets the message priority after dequeuing
// Checks if any message with correlation like 'SCOTT' is available on the queue.
int DequeueObject()
     ODatabase odb;
     OAQ oaq;
     OAQMsg oaqmsg;
     const char *msgid = 0;
     OValue msg;
     char subject[255];
     char text[255];
     odb.Open(osess, "MICROSOFT", "OMNIPOS", "OMNIPOS");
     if ( ! odb.IsOpen() )
          cout << "Database not opened: " << odb.GetErrorText() << endl;
          odb.Close();
          return(-1);
     // Open the 'msg_queue'
     oaq.Open(odb,"example_queue");
     if( !oaq.IsOpen())
          cout << "AQ not opened: " << oaq.GetErrorText() << endl;
          return(-1);
     // Get an instance of the udt MESSAGE_TYPE (check out schema for details)
     oaqmsg.Open(oaq,1,"MESSAGE_TYPE");
     if( !oaqmsg.IsOpen() )
          cout << "AQMsg not opened: " << oaqmsg.GetErrorText() << endl;
          return(-1);
     // Dequeue message with correlation like "SCOTT"
     oaq.SetCorrelate("%OMNIPOS%");
     oaq.SetDequeueMode(3);
     msgid = oaq.Dequeue();
     if (msgid )
          // Retrieve the message attributes
          // Get the subject,text attributes of the message
          OObject msgval;
          oaqmsg.GetValue(&msgval);
          msgval.GetAttrValue("subject", subject,255);     
          msgval.GetAttrValue("text", text,255);
          cout << "Message '" << (subject ? subject :"") << "' & Body : '" << text <<
               "' dequeued at priority : " << oaqmsg.GetPriority() << endl;
          msgval.Close();
     msgid = 0;
     oaq.SetNavigation(1);
     oaq.SetCorrelate("");
     // Dequeue a message
     msgid = oaq.Dequeue();
     if (msgid )
          // Retrieve the message attributes
          OObject msgval;
          oaqmsg.GetValue(&msg);
          msgval = msg;          
          // Get the subject,text attributes of the message
          msgval.GetAttrValue("subject", subject,255);     
          msgval.GetAttrValue("text", text,255);
          cout << "Message '" << (subject ? subject :"") << "' & Body : '" << text <<
               "' dequeued at priority : " << oaqmsg.GetPriority() << endl;
          msgval.Close();
     // Close all of the objects
     msgid = NULL;
     msg.Clear();
     oaqmsg.Close();
     oaq.Close();
     odb.Close();
     return 0;
}