public InvoiceSubTableCollection FetchByQuery(Query qry)
        {
            InvoiceSubTableCollection coll = new InvoiceSubTableCollection();

            coll.LoadAndCloseReader(qry.ExecuteReader());
            return(coll);
        }
        public InvoiceSubTableCollection FetchAll()
        {
            InvoiceSubTableCollection coll = new InvoiceSubTableCollection();
            Query qry = new Query(InvoiceSubTable.Schema);

            coll.LoadAndCloseReader(qry.ExecuteReader());
            return(coll);
        }