c# data table query not exist joins

Question

I am bit confused with C# LINQ queries. I have a table with values as shown below

DataTable tableold = new DataTable();
tableold.Columns.Add(\"Dosage\", typeof(i         


        

Answer 1

Try this:

 var compare= tableold.AsEnumerable().Select(r => r.Field("Dosage"))
         .Except(tableNew.AsEnumerable().Select(r => r.Field("Dosage")));
 DataTable tblResult= (from row in tableold.AsEnumerable()
                                join id in compare
                                on row.Field("Dosage") equals id
                                select row).CopyToDataTable();