Sql Net Linq with datatables-从一个表中选择另一个表中不存在的内容

我有两个数据，我应用linq选择了一些行：

csql = "select * from V_Vente where code_projet=" & ComProjet.GetColumnValue("code_projet") & " "
Dim tabVnt as Datatable = utilitaire.getDatatable(csql)

Dim query1 = tabVnt.AsEnumerable().Where(Function(r) DirectCast(r("date"), Date) >= dtDu And DirectCast(r("date"), Date) <= dtAu)

Dim tabAnnule As DataTable = utilitaire.getDatatable("select  * from V_Reserv_Annule")
Dim query2 = From cust In tabAnnule.AsEnumerable() Where (cust.type = "définitif" Or cust.type = "Transfert") And cust.date_annule <= dtAu

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如果我正确理解了您的代码，您可以检查第二个表的

Num\u r

s是否不包含表一

Num\u r

：

Dim rows = t1.Where(x=> !t2.Select(y=> y.Num_r).Contains(x.Num_r));

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我已经找到了我的问题的解决方案，我想在这里与您分享：

Dim csql = "select * from V_Vente where code_projet=" & ComProjet.GetColumnValue("code_projet") & " "
Dim tabVnt As DataTable = utilitaire.getDatatable(csql) 

Dim query1 = tabVnt.AsEnumerable().Where(Function(r) DirectCast(r("date"), Date) >= dt1 And DirectCast(r("date"), Date) <= dt2).ToList

Dim tabAnnule As DataTable = utilitaire.getDatatable("select  * from V_Reserv_Annule")

  bannedCCList = From c In tabAnnule.AsEnumerable() _
                 Where (c!type.Equals("définitif") = True Or c!type.Equals("Transfert") = True) And c!date_annule <= dt2
                 Select c.Field(Of String)("num_recu")

   Dim exceptData = (From c In query1.AsEnumerable() _
                    Where Not bannedCCList.Contains(c.Field(Of String)("num_recu")) _
                    ).ToList

Dim csql=“从V_Vente where code_projet=“&ComProjet.GetColumnValue（“code_projet”）&”中选择*
Dim tabVnt As DataTable=utilitaire.getDatatable（csql）
Dim query1=tabVnt.AsEnumerable（）。其中（函数（r）DirectCast（r（“日期”），date）>=dt1和DirectCast（r（“日期”），date）
Dim csql = "select * from V_Vente where code_projet=" & ComProjet.GetColumnValue("code_projet") & " "
Dim tabVnt As DataTable = utilitaire.getDatatable(csql) 

Dim query1 = tabVnt.AsEnumerable().Where(Function(r) DirectCast(r("date"), Date) >= dt1 And DirectCast(r("date"), Date) <= dt2).ToList

Dim tabAnnule As DataTable = utilitaire.getDatatable("select  * from V_Reserv_Annule")

  bannedCCList = From c In tabAnnule.AsEnumerable() _
                 Where (c!type.Equals("définitif") = True Or c!type.Equals("Transfert") = True) And c!date_annule <= dt2
                 Select c.Field(Of String)("num_recu")

   Dim exceptData = (From c In query1.AsEnumerable() _
                    Where Not bannedCCList.Contains(c.Field(Of String)("num_recu")) _
                    ).ToList