如何在两个给定日期之间选择最近注册的数据

Question

如何使用C＃中的数据集从数据库中获取最近注册的数据。

我想在两个给定日期之间获取最近注册的数据。 在开始月份之前，数据不得存在。

请帮助我，因为我被困在这里。

public DataSet getRecentRegistrations(DateTime startMonth, DateTime endMonth, long setaCode)
{
    var query = (from _transaction in _entities.LevyTransactions
                 join _seta in _entities.Setas on _transaction.SetaCode equals _seta.SetaCode
                 join company_details in _entities.Organisations on _transaction.Refno equals company_details.Refno
                 where(_transaction.TransactionDate >= startMonth || startMonth == null) && (_transaction.TransactionDate <= endMonth || endMonth == null) && (_transaction.SetaCode == setaCode || setaCode < 0)
                 select new
                 {
                     SetaCode= _transaction.SetaCode,
                     RefNo = company_details.Refno,
                     TradingName = company_details.TradingName,
                     Seta=_transaction.SetaCode+" - "+_seta.Description,
                     SetaLevy = _transaction.SetaLevy,
                     SetaInterest = _transaction.SetaInterest,
                     SetaAdmin = _transaction.SetaAdmin,
                     SetaPenalty = _transaction.SetaPenalty,
                     TotalSetaCollected = _transaction.TotalSetaCollected
                 });

    DataSet ds = new DataSet();
    ds.Tables.Add(query.CopyToDataTable()); ds.Tables[0].TableName = "Table1";
    ds.Tables.Add(headerTable("Transaction Month From : " + HelperService.formatDate("yyyy-MM-dd", startMonth) + " To : " + HelperService.formatDate("yyyy-MM-dd", endMonth), "Recently Registered Companies")); ds.Tables[1].TableName = "Table2";
    var setaRows = (from DataRow dRow in ds.Tables[0].Rows
                    select new {
                                SetaCode = dRow["SetaCode"], Seta = dRow["Seta"] 
                                }).Distinct();
    ds.Tables.Add(setaRows.CopyToDataTable()); ds.Tables[2].TableName = "Table3";
    return ds;
}