public virtual void RefreshSchema()
    {
      this._dbSchemaTable = (DataTable) null;
      this._dbSchemaRows = (DbSchemaRow[]) null;
      this._sourceColumnNames = (string[]) null;
      this._quotedBaseTableName = (string) null;
      DbDataAdapter dataAdapter = this.DataAdapter;
      if (dataAdapter != null)
      {
        if (this.InsertCommand == dataAdapter.InsertCommand)
          dataAdapter.InsertCommand = (DbCommand) null;
        if (this.UpdateCommand == dataAdapter.UpdateCommand)
          dataAdapter.UpdateCommand = (DbCommand) null;
        if (this.DeleteCommand == dataAdapter.DeleteCommand)
          dataAdapter.DeleteCommand = (DbCommand) null;
      }
      DbCommand insertCommand;
      if ((insertCommand = this.InsertCommand) != null)
        insertCommand.Dispose();
      DbCommand updateCommand;
      if ((updateCommand = this.UpdateCommand) != null)
        updateCommand.Dispose();
      DbCommand deleteCommand;
      if ((deleteCommand = this.DeleteCommand) != null)
        deleteCommand.Dispose();
      this.InsertCommand = (DbCommand) null;
      this.UpdateCommand = (DbCommand) null;
      this.DeleteCommand = (DbCommand) null;
    }