Compare unique combination of Rows in 2 Datatable & find if they are same using LINQ

Question

DataSet oDs = new DataSet(); DataTable odt = new DataTable();

        odt.Columns.Add(new DataColumn("FILE_ID", typeof(string)));
        odt.Columns.Add(new DataColumn("ID", typeof(string)));
        oDs.Tables.Add(odt);
        oDs.AcceptChanges();

        for (int i = 1; i < 3; i++)
        {
            DataRow oDr = oDs.Tables[0].NewRow();
            oDr["FILE_ID"] = "a" + i;
            oDr["ID"] = "b" + i;
            oDs.Tables[0].Rows.Add(oDr);
        }
        for (int i = 1; i < 3; i++)
        {
            DataRow oDr = oDs.Tables[0].NewRow();
            oDr["FILE_ID"] = "c" + i;
            oDr["ID"] = "d" + i;
            oDs.Tables[0].Rows.Add(oDr);
        }
        oDs.AcceptChanges();

        DataTable odt1 = new DataTable();

        odt1.Columns.Add(new DataColumn("FILE_ID", typeof(string)));
        odt1.Columns.Add(new DataColumn("ID", typeof(string)));
        oDs.Tables.Add(odt1);
        oDs.AcceptChanges();

        for (int i = 1; i < 3; i++)
        {
            DataRow oDr = oDs.Tables[1].NewRow();
            oDr["FILE_ID"] = "a" + i;
            oDr["ID"] = "b" + i;
            oDs.Tables[1].Rows.Add(oDr);
        }
        for (int i = 1; i < 3; i++)
        {
            DataRow oDr = oDs.Tables[1].NewRow();
            oDr["FILE_ID"] = "c" + i;
            oDr["ID"] = "d" + i;
            oDs.Tables[1].Rows.Add(oDr);
        }
        oDs.AcceptChanges();

I need a LINQ query by which I can find if the combination of the values of rows (FILE_ID+ID) are unique & if they are the same in both the datatables

You have 2 tables. Each has multiple rows. So for a given table, you want to concatonate the row values (FILE_ID+ID) and compare that against the other rows of that table to determine if all results are unique? furthermore, you want to ensure both tables have the same content? — justin arsine, Feb 28 '13 at 16:32
I don't want to concatenate the two rows but the combination of the values in a row must be unique and to ensure that both the table has the same row combination — shiju87, Feb 28 '13 at 16:38

score 0 · Answer 1 · edited May 23 '17 at 11:43

This gets you the non-unique values:

var notUnique = odt.AsEnumerable()
                            .GroupBy(x => (string) x["FILE_ID"] + x["ID"])
                            .Where(g => g.Count() > 1);

Finding the values that are in one table but not the other is found here Compares

Your particular case would look like this:

  var differentRows =
            odt.AsEnumerable().Where(
                o =>
                odt1.AsEnumerable().All(
                    o1 => ((string) o["FILE_ID"] + o["ID"]) != ((string) o1["FILE_ID"] + o1["ID"])))
                .Union(odt1.AsEnumerable().Where(
                o1 => odt.AsEnumerable().All(o => ((string)o["FILE_ID"] + o["ID"]) != ((string)o1["FILE_ID"] + o1["ID"]))));

Keep in mind this is like the "except" method where duplicate records wont present themselves as a difference. But since you are checking for dupes above I will assume no further checking is req'd.

This query was right until there were no DBNull values in any columns. If by accidently any DBNULL.Value came in any DataTable there would be problems. — shiju87, Mar 01 '13 at 04:55

Compare unique combination of Rows in 2 Datatable & find if they are same using LINQ

1 Answers1