Пропуснете някои колони в SqlBulkCopy

DataTable table = new DataTable();
using (var adapter = new SqlDataAdapter(sourceCommand))
{
    adapter.Fill(table);
}

using (SqlBulkCopy bulk = new SqlBulkCopy(targetConnection, SqlBulkCopyOptions.KeepIdentity, null) { DestinationTableName = tableName })
{
    foreach (string columnName in GetMapping(stringSource, stringTarget, tableName))
    {
        bulk.ColumnMappings.Add(new SqlBulkCopyColumnMapping(columnName, columnName));
    }

    targetConnection.Open();
    bulk.WriteToServer(table);
}

private static IEnumerable<string> GetMapping(string stringSource, string stringTarget, string tableName)
{
    return Enumerable.Intersect(
        GetSchema(stringSource, tableName),
        GetSchema(stringTarget, tableName),
        StringComparer.Ordinal); // or StringComparer.OrdinalIgnoreCase
}

private static IEnumerable<string> GetSchema(string connectionString, string tableName)
{
    using (SqlConnection connection = new SqlConnection(connectionString))
    using (SqlCommand command = connection.CreateCommand())
    {
        command.CommandText = "sp_Columns";
        command.CommandType = CommandType.StoredProcedure;

        command.Parameters.Add("@table_name", SqlDbType.NVarChar, 384).Value = tableName;

        connection.Open();
        using (var reader = command.ExecuteReader())
        {
            while (reader.Read())
            {
                yield return (string)reader["column_name"];
            }
        }
    }
}