Method Execute

IO/PostgreSQL/vtkPostgreSQLQuery.cxx:216–309

------------------------------------------------------------------------------

//------------------------------------------------------------------------------
bool vtkPostgreSQLQuery::Execute()
{
  if (this->Query == nullptr)
  {
    vtkErrorMacro("Cannot execute before a query has been set.");
    return false;
  }

  vtkPostgreSQLDatabase* db = vtkPostgreSQLDatabase::SafeDownCast(this->Database);
  assert(db);

  // If a query is already in progress clear out its results so we can
  // begin anew.
  if (this->QueryInternals)
  {
    this->DeleteQueryResults();
  }

  if (!db->IsOpen())
  {
    this->SetLastErrorText("Cannot execute query.  Database connection is closed.");
    vtkErrorMacro(<< "Cannot execute query.  Database connection is closed.");
    this->Active = false;
    return false;
  }

  this->QueryInternals = new vtkPostgreSQLQueryPrivate;
  this->QueryInternals->QueryResults = PQexec(db->Connection->Connection, this->Query);

  bool returnStatus;
  switch (PQresultStatus(this->QueryInternals->QueryResults))
  {
    case PGRES_EMPTY_QUERY:
    {
      returnStatus = true;
      this->Active = false;
      this->DeleteQueryResults();
      vtkWarningMacro(<< "Query string was set but empty.");
      this->SetLastErrorText(nullptr);
    };
    break;

    case PGRES_COMMAND_OK: // success on a command returning no data
    {
      returnStatus = true;
      this->Active = true;
      this->DeleteQueryResults();
      this->SetLastErrorText(nullptr);
    };
    break;

    case PGRES_TUPLES_OK:
    {
      returnStatus = true;
      this->Active = true;
      this->SetLastErrorText(nullptr);
    };
    break;