如何在Web窗体应用程序中使用asp.net c＃将Excel数据上载到具有自动递增ID字段的SQL Server表中？

Question

I read through a terrific post from Mudassar Ahmed Khan at http://www.aspsnippets.com/Articles/Import-Upload-CSV-file-data-to-SQL-Server-database-in-ASPNet-using-C-and-VBNet.aspx . It covers how to upload an Excel file into a SQL Server database table using asp.net and C#.

It works just fine, but I would like to get it to work for a table where the Id column is auto incremented. I would like to know how to modify the code to allow users to upload the file without having to specify a value for the Id column.

Any help would be greatly appreciated.

I'm using the code provided in the aforementioned tutorial as-is - I didn't make any changes. I'm just trying to understand how before I attempt to apply it to my actual application.

Please let me know if I need to provide additional information.

Any help would be greatly appreciated.

Thanks, J

Here is the code I would like to modify:

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();

       //[OPTIONAL]: It is recommended as otherwise the data will be considered as String by default.
       dtExcelData.Columns.AddRange(new DataColumn[3] { new DataColumn("Id", typeof(int)),
            new DataColumn("Name", typeof(string)),
            new DataColumn("Salary",typeof(decimal)) });

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

       excel_con.Close();

       string consString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;

       using (SqlConnection con = new SqlConnection(consString))
       {
           using (SqlBulkCopy sqlBulkCopy = new SqlBulkCopy(con))
           {
                //Set the database table name
                sqlBulkCopy.DestinationTableName = "dbo.tblPersons";

                //[OPTIONAL]: Map the Excel columns with that of the database table
                sqlBulkCopy.ColumnMappings.Add("Id", "PersonId");
                sqlBulkCopy.ColumnMappings.Add("Name", "Name");
                sqlBulkCopy.ColumnMappings.Add("Salary", "Salary");

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

Here is the aspx page markup:

<asp:FileUpload ID="FileUpload1" runat="server" />
<asp:Button Text="Upload" OnClick = "Upload" runat="server" />

Here are the Excel specific connection strings for Excel 2003 and Excel 2007 or higher formats:

<add name = "Excel03ConString" connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties='Excel 8.0;HDR=YES'"/>
<add name = "Excel07+ConString" connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties='Excel 8.0;HDR=YES'"/>

Answer 1

Since you can'nt use an identity column for bulkcopy you can add a column to the datatable:

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

dtExcelData.Columns.Add("Id", typeof(int));

int i = 0;
foreach(DataRow dr in dtExcelData.Rows)
{
    dr["Id"] = ++i;  
}
//...