The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 4: FILESTREAM with Entity Framework and LINQ to SQLRetrieving information from the databaseNow, let us see how to retrieve data from FILESTREAM columns using EF. Just as wesaw in the previous example, there is no FILESTREAM-specific code involved in this stepeither. EF treats FILESTREAM columns as VARBINARY(MAX) columns, and thereforethe code that we will write will be the same for FILESTREAM and VARBINARY(MAX)columns.The code in Listing 4-5 searches for a record with ItemNumber IT001, and returns anItem object that contains the information about the given record. The last part of thecode reads the FILESTREAM value stored in the ItemImage column and writes to a diskfile. Add the code to the Main() method in the Program class. You must also import theSystem.Data.Objects namespace at the top of your code file.NorthPoleEntities npe = new NorthPoleEntities();foreach (Item itm in npe.Items.Where("it.ItemNumber == IT001")){System.IO.File.WriteAllBytes("c:\\temp\\mm.jpg", itm.ItemImage);}npe.Dispose();Listing 4-5:Retrieving BLOB values stored in a FILESTREAM column.That completes Lab 2, in which we created a very simple console application thatdemonstrated how to read and write FILESTREAM values using EF. Run theapplication, or debug and step through the code, to see our code in action.143