Sharepoint 2010 External list

[Gautam]

How to add Attachment link to External list

[DigiOz Multimedia]

Do you mean attachments (aka attach files to an external sharepoint site)? If so here is a code that should do the trick for you:

            try
            {
                WebClient loClient = new WebClient();
                loClient.Credentials = new NetworkCredential(Utility.GetConfigKey("SharePoint ACCOUNT"), Utility.GetConfigKey("SP Account Password"), "Domain Name");
                byte\[\] myDataBuffer = loClient.DownloadData(new Uri(Utility.GetConfigKey("SharePoint URL") + lsFileName));

                // Clear all content output from the buffer stream
                Response.Clear();
                // Add a HTTP header to the output stream that specifies the default filename
                // for the browser's download dialog
                Response.AddHeader("Content-Disposition", "attachment; filename=" + lsFileName);
                // Add a HTTP header to the output stream that contains the 
                // content length(File Size). This lets the browser know how much data is being transfered
                Response.AddHeader("Content-Length", myDataBuffer.Length.ToString());
                // Set the HTTP MIME type of the output stream
                Response.ContentType = "application/octet-stream";
                // Write the data out to the client.
                Response.BinaryWrite(myDataBuffer);
            }
            catch
            {
                lblFormError.Text = "Unable to add document to sharepoint list location";
            }

Pete Soheil DigiOz Multimedia http://www.digioz.com