The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 5: FILESTREAM with ASP.NET and SilverlightNote that this stored procedure inserts a dummy value into the FILESTREAM columnbecause, as we have already seen in Chapter 3, Win32/Managed API access to aFILESTREAM column is possible only if the column is non-NULL.The stored procedure returns a result set that contains the PathName(), the logicalidentifier pointing to the disk file associated with the FILESTREAM column in the newlyinserted row, and a FILESTREAM transaction context of the currently active transaction.This is done to avoid an additional database call when writing the code to save theFILESTREAM data. For more information, refer back to Chapter 3.Saving the FILESTREAM dataAfter the relational data is saved, we will execute the code to save the FILESTREAM datausing the FILESTREAM Managed API. We saw in Chapter 3 an example of how to load thecontent of a disk file into the FILESTREAM column. In this case, we will obtain a streampointing to the file selected by the user through the FileContent property of the fileupload control (Listing 5-8).private void SaveItem(){//Create and open a database connectionSqlConnection cn = new SqlConnection();cn.ConnectionString =System.Configuration.ConfigurationManager.ConnectionStrings["NorthPoleDB"].ToString();Cn.Open();//Create a Command objectSqlCommand cmd = new SqlCommand();cmd.CommandText = "SaveItemImage";cmd.Connection = cn;cmd.CommandType = CommandType.StoredProcedure;cmd.Parameters.AddWithValue("@ItemNumber", txtItemNumber.Text);cmd.Parameters.AddWithValue("@ItemDescription",txtItemDescription.Text);173