c# - 如何使用 asp.net SqlBulkCopy 比较 excel 值？

Question

我正在将 Excel 工作表导入 SQL Server 数据库。Excel 工作表包含 3 列

id|data|passport

我在用SqlBulkCopy

SqlConnection con = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["constr"].ConnectionString);

    string[] filePaths = null;
    string strFileType = null;
    string strFileName = null;
    string strNewPath = null;
    int fileSize;
    int flag=0;

    protected void Page_Load(object sender, EventArgs e)
    {
    }

    protected void Button1_Click1(object sender, EventArgs e)
    {
        strFileType = System.IO.Path.GetExtension(FileUpload1.FileName).ToString().ToLower();
        strFileName = FileUpload1.PostedFile.FileName.ToString();
        FileUpload1.SaveAs(Server.MapPath("~/Import/" + strFileName + strFileType));
        strNewPath = Server.MapPath("~/Import/" + strFileName + strFileType);
        fileSize = FileUpload1.PostedFile.ContentLength / 1024;

        //EXCEL DETAILS TABLE
        con.Open();
        //=========================================
        DataTable dt8 = new DataTable();
        SqlCommand cmd8 = new SqlCommand("insert into exceldetails (name,type,details,size)" + "values(@name,@type,@details,@size)", con);
        cmd8.Parameters.Add("@name", SqlDbType.VarChar).Value = strFileName;
        cmd8.Parameters.Add("@type", SqlDbType.VarChar).Value = strFileType;
        cmd8.Parameters.Add("@details", SqlDbType.VarChar).Value = DateTime.Now;
        cmd8.Parameters.Add("@size", SqlDbType.Int).Value = fileSize;
        cmd8.ExecuteNonQuery();
        con.Close();
        try
        {
            SqlDataAdapter da8 = new SqlDataAdapter(cmd8);
            da8.Fill(dt8);
        }
        catch { }
        //=========================================

        //CHOOSING EXCEL CONNECTIONSTRING

        string excelConnectionString = "";
        switch (strFileType)
        {
            case ".xls":

                excelConnectionString = String.Format(@"Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + strNewPath + "; Extended Properties=Excel 8.0;");
                break;
            case ".xlsx":
                {
                    excelConnectionString = String.Format(@"Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + strNewPath + "; Extended Properties=Excel 12.0 Xml;");

                    break;
                }
        }

        //===================================
        //PRE EXCEL COUNT

        // Create Connection to Excel Workbook
        using (OleDbConnection connection = new OleDbConnection(excelConnectionString))
        {
            connection.Open();
            OleDbCommand command = new OleDbCommand("Select ID,Data,passport FROM [Sheet1$]", connection);
            OleDbCommand command1 = new OleDbCommand("select count(*) from [Sheet1$]", connection);

            //Sql Server Table DataTable
            DataTable dt4 = new DataTable();
            SqlCommand cmd4 = new SqlCommand("select * from excelsheet", con);
            try
            {
                SqlDataAdapter da4 = new SqlDataAdapter(cmd4);
                da4.Fill(dt4);//sql table datatable
            }
            catch { }

            //===============================

            //excelsheet datatable
            DataTable oltlb = new DataTable();
            OleDbCommand olcmd = new OleDbCommand("select * from [Sheet1$]", connection);
            try
            {
                OleDbDataAdapter olda = new OleDbDataAdapter(olcmd);
                olda.Fill(oltlb); //excel table datatable
            }
            catch { }

            //==============================


            using (DbDataReader dr = command.ExecuteReader())
            {
                // SQL Server Connection String
                string sqlConnectionString = "Data Source=DITSEC3;Initial Catalog=test;Integrated Security=True";

                con.Open();
                DataTable dt7 = new DataTable();
                dt7.Load(dr);
                DataRow[] ExcelRows = new DataRow[dt7.Rows.Count];
                DataColumn[] ExcelColumn = new DataColumn[dt7.Columns.Count];

                //=================================================
                for (int i1 = 0; i1 < ExcelRows.Length; i1++)
                {
                    string a = ExcelRows[i1]["passport"].ToString();
                    char a1 = a[0];

                    if (a1 >= 'A' || a1 <= 'Z')
                    {
                        Label12.Text = "CAPITAL";
                        break;
                    }
                    else
                    {
                        Label12.Text = "notgood";


                        flag = flag + 1;



                    }

                }
                //=========================================================

                if (flag == 0)
                {
                    using (SqlBulkCopy bulkCopy = new SqlBulkCopy(sqlConnectionString))
                    {
                        bulkCopy.DestinationTableName = "ExcelTable";
                        dt7.Rows.CopyTo(ExcelRows, 0);

                        //==========================================================================================
                        for (int i = 0; i < ExcelRows.Length; i++)
                        {
                            if (ExcelRows[i]["passport"] == DBNull.Value)
                            {
                                ExcelRows[i]["passport"] = 0;
                            }

                        }
                        bulkCopy.WriteToServer(ExcelRows);
                        //==========================================================================================
                        for (int i = 0; i < ExcelRows.Length; i++)
                        {
                            if (ExcelRows[i]["data"] == DBNull.Value)
                            {
                                // Include any actions to perform if there is no date
                                //ExcelRows[i]["data"] = Convert.ToDateTime("0");
                            }
                            else
                            {
                                DateTime oldDate = Convert.ToDateTime(ExcelRows[i]["data"]).Date;
                                DateTime newDate = Convert.ToDateTime(oldDate).Date;
                                ExcelRows[i]["data"] = newDate.ToString("yyyy/MM/dd");
                            }

                        }

                        //==========================================================================================
                    }
                    //======

                }
                else
                {
                    Label13.Text = "Wrong Format";
                }
            }

        }
    }
}

错误：

string a = ExcelRows[i1]["passport"].ToString();

错误：

你调用的对象是空的。