The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 6: FILESTREAM with SSIS and SSRSSo far, we have obtained a Connection object pointing to the target database, andidentified the ID of the item to be processed.The approach presented in this lab does a round trip to the server at each iteration of theloop. This is to keep the duration of FILESTREAM transactions minimal. Remember thatall access to the FILESTREAM data should be made within the scope of a transaction.An alternative approach would be to start a transaction at the beginning of the processand fetch the PathName() of all the rows with a single database call. In this case, theadditional round trips to the server can be avoided. However, this approach will keep atop level transaction open until the process completes, which could block the requestsfrom other connections.We now need a few local variables to store the FILESTREAM transaction context, thelogical path name of the FILESTREAM data value, and the path to the disk file that wewant to load into the FILESTREAM column, as shown in Listing 6-12.byte[] FSContext = null;string FSPathName = string.Empty;string FileName = string.Empty;Listing 6-12:Setting up the local variables.Next, we'll start a database transaction and execute the stored procedure (Listing 6-13).SqlCommand cmd = new SqlCommand();cmd.Connection = con;cmd.CommandText = "GetItemInfo";cmd.CommandType = CommandType.StoredProcedure;cmd.Parameters.AddWithValue("@ItemID", ItemID);SqlTransaction transaction = con.BeginTransaction("ItemTran");cmd.Transaction = transaction;SqlDataReader reader = cmd.ExecuteReader();Listing 6-13:Starting a database transaction and executing the stored procedure.251