I have two data on which I have applied the linq to select some lines :

```
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

```

now what i want is to select rows from "query1" where "Num\_R" not exist in "query2".
The column "Num\_r" exist in both datatable "tabVnt" and "tabAnnule"
I've tried this code but he doesn't work,please help me to find the error :

```
dim rows = from t1 in query1 .AsEnumerable() join t2 in query2.AsEnumerable() on t1.Field(Of String)("Num_r") equals t2.Field(Of String)("Num_r") Into tg
        From tcheck In tg.DefaultIfEmpty()
        Where tcheck = null
        Select t1()

```