何时或如何在QSqlTableModel上用一个SQLite数据库来使用fetchMore()来工作?

My class DataTable is derived from QAbstractTableModel. It uses a QSqlTableModel object internally to fetch data from a db table. It represents a record for every row in the db (it does more but the record count is always the number of rows in the db table).My class DataTable is derived from QAbstractTab