LINQ: Comparing specific values in two datatables

Question

This question already has an answer here:

• How to compare 2 dataTables 11 answers

I have two datatables.

datatable 1 has data with columns FirstName, LastName, DOB, Gender datatable 2 has data with columns CustomerID, FirstName, LastName, DOB, Gender

I want to compare the firstName, LastName, DOB and gender in datatable 1 and 2, and if there is a match, load that row in datatable 2 into a new datatable.

Below is what I am using, I can compare with Firstname, but I want to add the lastname, DOB and gender. Please can you show me how I can do that?

I want to do it such that if firstname, lastname, dob and gender match then return that matching row in datatable 2. The column length between the tables are different.

DataTable dtMerged = (from a in dataTable.AsEnumerable()
                                  join b in dt.AsEnumerable()
                                  on a["Forename"].ToString() equals b["FirstName"].ToString()
                                  into g
                                  where g.Count() > 0
                                  select a).CopyToDataTable();

            dtMerged.AsDataView();

Answer 1

Try this

DataTable dtMerged = dataTable.AsEnumerable()
    .Where(ra => dt.AsEnumerable()
    .Any(rb => rb.Field<string>("firstname") == ra.Field<string>("firstname")
      && rb.Field<string>("lastname") == ra.Field<string>("lastname")
      && rb.Field<DateTime>("dob") == ra.Field<DateTime>("dob")
      && rb.Field<string>("gender") == ra.Field<string>("gender")))
              .CopyToDataTable();