🚀 go-pugleaf

I am using BCB6 Enterprise to create a web service (primarily using the Web
App Debugger for now). My web service must open a query to an Oracle table
when the service starts up. My database connection start up code looks like
this:

   // Create connection to Oracle database
   FOracleConnection = new TADOConnection(Application);
   FOracleConnection->LoginPrompt = false;

   // Create main data access point
   FQuery = new TADOQuery(FOracleConnection);

   FOracleConnection->ConnectionString = WideString(...);
   FOracleConnection->Open(...);
   if (FOracleConnection->Connected)
   {
         FQuery->Connection = FOracleConnection;
         FQuery->SQL->Text = "select ...";
         FQuery->LockType = ltOptimistic;
         FQuery->Prepared = true;
         FQuery->Open();
   } // if Connected

Then my service does some stuff. Then it closes down:

   FQuery->Close();
   delete FQuery;

   // Close Oracle database connection
   FOracleConnection->Close();
   delete FOracleConnection;

If I allow the query to use dynamic fields, everything works just fine.
Unfortunately, one of the fields in the query is a data type of "DECIMAL(20,
0)", which none of the dynamic field types handle properly. So, I need to
override the field types using my own defined persistent field objects.

   FField1 = new TVariantField(FQuery);
   FField1->FieldName = ...;
   FField1->DataSet = FQuery;
   FQuery->Fields->Add(FField1);

And so on. Everything works fine until I try to delete the query object:

   FQuery->Close();
   FQuery->Fields->Remove(FField1);
   delete FField1;
   delete FQuery;

The "delete FQuery;" statement generates an access violation at an address
residing deep in the ADO source code. But, only when I use persistent
fields.

Does anyone know why this might be happening? Please help me!

Dan