SQL Bulk Copy with duplicate keys

Given:
- Large xml file containing entries that need to be in my database table. Some rows have same value for the table key (not necessarily completely duplicate rows!)
- SQL table, C# code

Problem:
Copy the entries from xml to SQL table. This is done fast using SQLBulkCopy function in .NET, but does not tolerate when input data has duplicate values for the primary key column. I really do not care about keeping the rows that are duplicate. Just throw them out so I can use the bulk copy for the 99% of the data.

Solutions.
Online blogs suggest a number of solutions:

- One is to create a temporary table with no duplicate entry constraints, bulk copy everything into that and then use SQL to copy temp table into the final table while maintaining constraints.

- Another way is to find all duplicate rows in a table in code, using hashtables.

- Next, using the Table.DefaultView.ToTable(distinct=true, columns), but this only removes duplicate rows, not  rows that have a certain column with duplicates.

- There is a way to do that with LINQ but I didn't even get to read that.

-------

I used a pretty short (imo) and fast way to do it using IEqualityComparer interface:

class RowEqualityComparer : IEqualityComparer

{

    public bool Equals(DataRow b1, DataRow b2)

    {

        return ((string)b1["Symbol"]) == ((string)b2["Symbol"]);

    }

    public int GetHashCode(DataRow b1)

    {

        // I'm not really sure what to do here or whether I should even worry

        return b1["Symbol"].GetHashCode();

    }

}

and then simply 

BulkCopy.WriteToServer(
           dst.Tables[table].AsEnumerable().Distinct(

               new RowEqualityComparer()).CopyToDataTable());

instead of 

sbc.WriteToServer(dst.Tables[table]);