Here's a quick piece of code from Martin Kusl on how to retrieve table names on the specified DNS:

    // List DNS:
    WString name;
    WString desc;
    WBool r=true;
    while( transaction->GetDataSourceInfo(&name,&desc,r) )
    {
       //name & desc
       r=false;
    }
    
    // ListTables on DNS:
    transaction->SetDataSource( DNS_NAME );
    if( !transaction->Connect() )   return false;
    WODBCDriver *drv=WODBCDriver::Load();
    if( !drv )    return false;
    if( !query->SetTransactionObject(transaction) )   return false;
    HSTMT stmt=(HSTMT)query->GetHandle();
    if( !stmt )   return false;

Another tip from Herbert Menke... This one about using shared data segments with Power++:

Although Power++ does not support shared data segments, it is possible to use shared data by separating shared and non-shared data segments.

1. Declare the data to be shared with the __far keyword, to put it into its own FAR_DATA segment. Example: WLong __far usageCount;
2. Link with the directive "segment class FAR_DATA shared". To set the directive to the linker you have to change the target file of the project:
   Change:
   (at)begin IDE_Command
       IDE_Command_Tool "WLINK";
       IDE_Command_Options "debug dwarf option incremental='$^*.ilk' .................
       IDE_Command_Def_Opt "debug dwarf option incremental='$^*.ilk' .................
   To:
   (at)begin IDE_Command
       IDE_Command_Tool "WLINK";
       IDE_Command_Options "Segment class FAR_DATA shared debug dwarf option incremental='$^*.ilk' ..............
       IDE_Command_Def_Opt "Segment class FAR_DATA shared debug dwarf option incremental='$^*.ilk' .................
   Note: Because this section exists two times in the target file (for release and debug builds), it must be changed twice.
3. To have a simple mechanism for synchronising access to a variable that is shared by multiple threads, use InterlockedIncrement, InterlockedDecrement and InterlockedExchange. If you have no Win32 SDK or if you don't want to include it, you can use the following prototypes:

   extern "C" WDLLIMPORT WLong InterlockedIncrement( WLong * lpVariableAddress );
   extern "C" WDLLIMPORT WLong InterlockedDecrement( WLong * lpVariableAddress );
   extern "C" WDLLIMPORT WLong InterlockedExchange( WLong * lpVariableAddress, WLong newValue );

Herbert Menke writes in with a tip about changing the look of the progress bar using the new common controls:

With new versions of the comctl32.dll (versions 4.70 and 4.71), the progressbar has 2 new styles and a function to change the colour of the bar.

If you want a smooth bar instead of the default segmented bar (v4.70):
progb_1->SetStyle( progb_1->GetStyle() | WStyle(1), true);

To display the progress status vertically, from bottom to top (v4.70):
progb_1->SetStyle( progb_1->GetStyle() | WStyle(4), true);

Finally, if you want to change to colour of the bar (v4.71):
progb_1->SendMessage(WMessage( 0x409, 0, color.GetRGB()));

You can download the newest version of comctl32 at: http://www.microsoft.com/msdn/downloads/files/40Comupd.exe.

Nat Vinod writes in with a tip on how to gain access to a database using one connection established by PowerBuilder by passing the dbhandle by using the PB function dbhandle():

Sharing a database transaction handle between PowerBuilder (or another development tool) and Power++: Note: In the example below the handle passed can be the GetConnectionHandle() from another Power++ transaction object or DBHandle() from PowerBuilder.

// Declare following instance variables:
WTransaction sqlca;
WQuery query;

// Create or Init function

long WDLLEXPORT InitTrans( unsigned long handle )
{
  bool ok;
  ok = sqlca.Create( "ODBC" );  // Creates the ODBC transaction object
  // Below statement borrows the transaction object.
  // However transaction is not a ref counted object and the set
  // method does not set the connected property of sqlca to true.
  ok = sqlca.SetConnectionHandle( handle );
  ok = qry->Create( &sqlca );  // Connects the query to transaction
                  // this fails to call the query's
                  // connect method.
  WODBCQuery * qry;
  qry = (WODBCQuery *) query.GetQueryObject();
  ok = qry->Connect();// Connects the query to transaction
            // this should have been done by
            // the Create call above but it did
            // not because sqlca's connected
            // property is false.
  // Now it is possible to user qry or query because query
  // redirects calls to qry. The query object now uses the
  // borrowed transaction and can get its benefits.
  ok = qry->SetSQL( "SELECT current user FROM DUMMY" );
  ok = qry->Open();
  ok = qry->MoveNext();
  WString s = qry->GetValue( 1 ).GetCHAR();
  ok = qry->Close();  // Calls Disconnect of query.
  WMessageBox::Info( NULL, "", s );
  return 1;
}

The key is to call the connect method of WODBCQuery. I have only tested this with ODBC transactions.