如何在oracle数据库中存储空数据（空）

Question

实际上，我需要将所有数据从excel插入到oracle数据库。在下面的程序中，我正在使用对象数组存储表中使用的所有不同类型的数据类型。这样做时，我无法将空值存储在对象数组中。

             public partial class _Default : System.Web.UI.Page
        {


   protected void Button1_Click(object sender, EventArgs e)
  {

    /* string ex_name = "";
     string ex_school = "";
     string ex_id = "";
     string ex_college = "";
     string ex_office = "";  */
    Excel.Application xlApp;
    Excel.Workbook xlWorkBook;
    Excel.Worksheet xlWorkSheet;
    Excel.Range range;

    //string str;
    int rCnt;
    int cCnt;
    int rw = 0;
    int cl = 0, i = 0;

    xlApp = new Excel.Application();
    xlWorkBook = xlApp.Workbooks.Open(@"C:\Shanmugavel\Book1.xlsx", 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
    xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);

    range = xlWorkSheet.UsedRange;





    rw = range.Rows.Count;
    cl = range.Columns.Count;

    object[] array1 = new object[100];
    int k = 0;
    for (rCnt = 1; rCnt <= rw; rCnt++)
    {
        for (cCnt = 1; cCnt <= cl; cCnt++)
        {


            array1[k] = (range.Cells[rCnt, cCnt] as Excel.Range).Value2;
            if (array1[k]==null)
            {
                array1[k] = null;
            }
            k++;

        }
        try
        {
            string oradb = "Provider=**;Data Source=**;User Id=**;Password=**;";

            string cmdText = @"INSERT INTO table_name
                     (SESSION_ID,TERRITORY_ID,SCANNER_SERIAL_NUM,RESPONDENT_ID,HOUSEHOLD_ID,QUESTIONAIRE_ID,SECTION_ID,QUESTION_ID,TEMPLATE_ID,DETAILS_ID,DATA,TIME_STAMP,INSERTED_DATE) 
                     VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?)";
            OleDbConnection con = new OleDbConnection(oradb);


            con.Open();


            OleDbCommand cmd = new OleDbCommand(cmdText, con);

            cmd.Parameters.Add("p1", OleDbType.VarChar).Value = array1[0];
            cmd.Parameters.Add("p2", OleDbType.VarChar).Value = array1[1];
            cmd.Parameters.Add("p3", OleDbType.VarChar).Value = array1[2];
            cmd.Parameters.Add("p4", OleDbType.VarChar).Value = array1[3];
            cmd.Parameters.Add("p5", OleDbType.VarChar).Value = array1[4];
            cmd.Parameters.Add("p6", OleDbType.VarChar).Value = array1[5];
            cmd.Parameters.Add("p7", OleDbType.VarChar).Value = array1[6];
            cmd.Parameters.Add("p8", OleDbType.VarChar).Value = array1[7];
            cmd.Parameters.Add("p9", OleDbType.VarChar).Value = array1[8];
            cmd.Parameters.Add("p10", OleDbType.VarChar).Value = array1[9];
            cmd.Parameters.Add("p11", OleDbType.VarChar).Value = array1[10];
            cmd.Parameters.Add("p12", OleDbType.VarChar).Value = array1[11];
            cmd.Parameters.Add("p13", OleDbType.VarChar).Value = array1[12];
            //cmd.Parameters.Add("p14", OleDbType.VarChar).Value = array1[13];

            k = 0;
            i = cmd.ExecuteNonQuery();

            con.Close();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }

    }
    if (i > 0)
    {
        Response.Write("Succesfull");
    }




    xlWorkBook.Close(true, null, null);
    xlApp.Quit();

    Marshal.ReleaseComObject(xlWorkSheet);
    Marshal.ReleaseComObject(xlWorkBook);
    Marshal.ReleaseComObject(xlApp);

}

}

显示错误，例如参数没有任何默认值 如果有人知道，请帮助我。

谢谢。