Question

I have used AsyncFileUpload AJAX control to upload a file to a column in a SQL Server database using LINQ to SQL. How do I retrieve the document from the database and allow the user to save to local drive using a Save As Dialog box using LINQ to SQL? This is ASP.NET web application. The DocumentFileContent database column is a Image SQL Server data type. Thanks

Answer 1

The best way in webforms is to use an HTTP handler.

The DB query for an image datatype will map to a byte[].

public class Document : IHttpHandler
{
    public void ProcessRequest(HttpContext context)
    {
        using (SQLConnection con = new SQLConnection)
        {
            SqlCommand command = new SqlCommand("SELECT imagefield FROM table", con);
            connection.Open();

            SqlDataReader reader = command.ExecuteReader();
            if (reader.HasRows)
            {
                while (reader.Read())
                {
                    context.Response.ContentType = "application/msword";
                    context.Response.BinaryWrite(reader["imagefield"]);
                }
            }
            reader.Close();
        }
    }

    public bool IsReusable
    {
        get
        {
            return false;
        }
    }
}