title: Lucene.Net How to Filter Results and Exclude an Array of IDs?
body: <p>I am working on an application that will need to suggest to a user some books he might want to purchase. Typically, a user might have already purchased some books, and we do not know these books at design time. I want to suggest to the user books he has not purchased.</p>
  
  <p>Since I am using lucene.net, I think what I need to do is to exclude the books the user has already purchased from the result to display to the user. So I could exclude an arbitrary (array) of BookIds the user has already purchase.</p>
  
  <p>Is it possible to achieve this in Lucene.NET? Could you please provide sample code if possible? Thanks.</p>