สอบถาม C# ในการ import text file แล้วลง MS sql จะต้องทำยังไงคับช่วยดูให้หน่อยคับว่าผิดพลาดยังไง

protected void btnImport_Click(object sender, EventArgs e)
        {
            if (FileUpload1.PostedFile.ContentType == "text" || FileUpload1.PostedFile.ContentType == "application/vnd.ms-excel")
            {
                string fileName = Path.Combine(Server.MapPath("~/ImportDocument"), Guid.NewGuid().ToString() + ".txt");
                try
                {
                    FileUpload1.PostedFile.SaveAs(fileName);

                    string[] Lines = File.ReadAllLines(fileName);
                    string[] Fields;

                    //Remove Header line
                    Lines = Lines.Skip(1).ToArray();
                    List<UploadFileTable> emList = new List<UploadFileTable>();
                    foreach (var line in Lines)
                    {
                        Fields = line.Split(new char[] { '\t' });
                        emList.Add(
                            new UploadFileTable
                            {
                                Plant = Fields[0].Replace("\"", ""), // removed "" 
                                Supplier_Code = Fields[1].Replace("\"", ""),
                                Supplier_Name = Fields[2].Replace("\"", ""),
                            });
                    }

                    // Update database data
                    using (MyData dc = new MyData())
                    {
                        foreach (var i in emList)
                        {
                            var v = dc.UploadFileTable.Where(a => a.Supplier_Code.Equals(i.Supplier_Code)).FirstOrDefault();
                            if (v != null)
                            {
                                v.Plant = i.Plant;
                                v.Supplier_Code = i.Supplier_Code;
                                v.Supplier_Name = i.Supplier_Name;
                            }
                            else
                            {
                                dc.UploadFileTable.Add(i);
                            }
                        }

                        dc.SaveChanges();

                        // populate updated data 
                        PopulateData();
                        lblMessage.Text = "Successfully Done. Now upto data is following.....";
                    }
                }