The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 3: Accessing FILESTREAM Data from Client Applications4. Read/Write FILESTREAM data – Read or write FILESTREAM data using the file I/Ofunctions.5. Close the FILESTREAM data file – Gracefully close the FILESTREAM data file.6. Commit/rollback the transaction – Commit or roll back the transaction when youhave finished.Let's examine each of these steps in detail.Step 1: Starting a transactionAll streaming access to FILESTREAM data, even just read access, must be done withinthe context of a database transaction so, before accessing the FILESTREAM data, yourapplication should start a SQL Server transaction.The exact manner in which you start a transaction on the current database connectionwill vary depending on the client library in use (ADO.NET, Open Database Connectivity,etc.). There is nothing FILESTREAM-specific in this step, you can just begin a transactionin the same way as for a T-SQL DML operation.We will see more detailed examples and fully functional sample code later in thischapter but, for now, Listing 3-1 shows a simple example of how to start a transactionon an ADO.NET connection object using C#.// Create a SqlConnection objectSqlConnection con = new SqlConnection("database=NorthPole;server=(local);integrated security=sspi;");//Open a connection to the databasecon.Open();//Start a transactionSqlTransaction transaction = con.BeginTransaction("ItemTran");Listing 3-1:Using C# to start a transaction on an ADO.NET connection object.91