The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 3: Accessing FILESTREAM Data from Client Applications// Begin a transactionSqlTransaction trn = con.BeginTransaction("ItemTran");cmd.Transaction = trn;// Execute the querySqlDataReader reader;reader = cmd.ExecuteReader();Listing 3-5:Using C# to retrieve the transaction context and logical path name ofa FILESTREAM data value.Step 3: Opening the FILESTREAM data fileThe next step is to open the FILESTREAM data file, using the wrapper function/classprovided by SQL Server. Direct access to the physical files stored in the FILESTREAM datacontainer can corrupt the database, so it's always advisable to access the data throughthese streaming APIs..NET developers can use the SqlFileStream object to access the FILESTREAM data.SqlFileStream exposes SQL Server data that is stored with the FILESTREAM columnas a sequence of bytes. It resides within the namespace System.Data.SqlTypes andwithin the assembly System.Data.dll. You must have .NET Framework 3.5 SP 1 or laterto use SqlFileStream class.SqlFileStream is derived from System.IO.Stream. Once you have a validSqlFileStream object representing the desired FILESTREAM data file, you canuse the Read(), Write() or the other "stream" functions available within the class tomanipulate your FILESTREAM data.Listing 3-6 shows how to open a FILESTREAM data file for reading.95