Using Linq for select row from DataTableA where id not in DataTableB - vb.net

Question

I have two dataTables ,and i want select all rows from DataTable1 where id is not in DataTable2.below what i have tried :
Sql = "select *,N°Reçu as NumRecu from V_Sit_J_Vente,V_Bien where V_Sit_J_Vente.Code_bien=V_Bien.Code_bien and date_situation <= '" + dt2 + "' and date_situation >= '" + dt1 + "'"
Dim GlobalDataVente As DataTable = utilitaire.getDataSet(Sql).Tables(0)
Sql = "select * from V_Reserv_Annule"
Dim GlobalDataAnnule As DataTable = utilitaire.getDataSet(Sql).Tables(0)
Dim query = (From order In GlobalDataVente.AsEnumerable() _
Where order!code_projet = tab.Rows(i).Item("code_projet")).ToList
Dim bannedCCList = From c In GlobalDataAnnule.AsEnumerable() _
Where c!type.Equals("Transfert acompte") = False And c!date_annule <= dt2
Dim exceptBanned = From c In query Group Join b In bannedCCList On c.Field(Of String)("N°Reçu") Equals b.Field(Of String)("num_reserv_remplace")
Into j() From x In j.DefaultIfEmpty() Where x Is Nothing Select c
What i want that "exceptBanned " containt all rows of "query" except row exist in "bannedCCList "
Thanks in advance

Answer 1

You can use Contains for this:
Dim query = (From order In GlobalDataVente.AsEnumerable() _
Where order!code_projet = tab.Rows(i).Item("code_projet")).ToList
Dim bannedCCList = From c In GlobalDataAnnule.AsEnumerable() _
Where c.type.Equals("Transfert acompte") = False And c.date_annule <= dt2
Select c.Field(Of String)("num_reserv_remplace")
Dim exceptBanned = From c In query
Where Not bannedCCList.Contains(c.Field(Of String)("N°Reçu"))
Select c
bannedCCList defines a query that produces the Id values you want to exclude; exceptBanned combines query with this list of Ids into a query that only runs once to return the final results. It works this way because bannedCCList is an IEnumerable. It isn't executed when it's defined, only when it's actually used.