title: How do I query unique documents from a meteor collection and avoid duplicates?
body: <p>I have a collection that contains thousands of documents in this form:</p>
  
  <pre><code>{
  "_id": "wMRHDpb53RhhjxXj4",
  "institution": "uw.edu",
  "campus": "seattle",
  "quarter": "SUMMER",
  "department": "CHEM",
  "course": "CHEM321",
  "section": "A",
  "ISBN": "",
  "createdAt": {
      "$date": "2017-08-13T18:20:40.923Z"
  },
  "ilendBooksId": "none",
  "ilendbooksId": "none"
  </code></pre>
  
  <p>}</p>
  
  <p>Each document represents a course at my school.
  EDIT: I have multiple documents that share every field except the date created. Based on that, what is the best solution? 
  I only want one document of each document that may exist of a different course. Can someone please help me? Thank you!</p>