Upload xls data into database table

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C#

ASP.NET

I am currently experiencing an error, whenever I try to upload xls datasheet into my database table. I am getting an exception error is:
Exception Details: System.InvalidCastException: Invalid cast from 'DateTime' to 'Single'.
The given value of type DateTime from the data source cannot be converted to type real of the specified target column.

This is my database table schema:

[id]
    ,[tag]
    ,[decimalP]
    ,[type]
    ,[UploadDate]
    ,[name]
FROM [dummy].[dbo].[database_data]

I tried adding a 'for loop' for sqlBulkCopy property for convert datetime, but I could not get that to work either.

Here is my Upload method:

protected void Upload(object sender, EventArgs e)
    {
        //Upload and save the file
        string excelPath = Server.MapPath("~/Files/") + Path.GetFileName(FileUpload1.PostedFile.FileName);
        FileUpload1.SaveAs(excelPath);

        string conString = string.Empty;
        string extension = Path.GetExtension(FileUpload1.PostedFile.FileName);
        switch (extension)
        {
            case ".xls": //Excel 97-03
                conString = ConfigurationManager.ConnectionStrings["Excel03ConString"].ConnectionString;
                break;
            case ".xlsx": //Excel 07 or higher
                conString = ConfigurationManager.ConnectionStrings["Excel07+ConString"].ConnectionString;
                break;

        }
        conString = string.Format(conString, excelPath);
        using (OleDbConnection excel_con = new OleDbConnection(conString))
        {
            excel_con.Open();
            string sheet1 = excel_con.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null).Rows[0]["TABLE_NAME"].ToString();
            DataTable dtExcelData = new DataTable();

            using (OleDbDataAdapter oda = new OleDbDataAdapter("SELECT * FROM [" + sheet1 + "]", excel_con))
            {
                oda.Fill(dtExcelData);
            }
            excel_con.Close();

            string consString = ConfigurationManager.ConnectionStrings["dummyConnectionString"].ConnectionString;
            using (SqlConnection con = new SqlConnection(consString))
            {
                using (SqlBulkCopy sqlBulkCopy = new SqlBulkCopy(con))
                {
                    //Set the database table name

                    sqlBulkCopy.DestinationTableName = "dbo.comp2";

                    con.Open();
                    sqlBulkCopy.WriteToServer(dtExcelData);
                    con.Close();
                }
            }
        }
    }

Any help would be very much appreciated.
Many thanks.