title: How to add to mongoDB(2.2.1) array from C#
body: <p>I'm having troubles understanding new mongoDB drivers for C#. In database, I have collection with array (comments: []). Now, I want to update(push) new comment to database, but with no success. I have tried various code, some are outdated etc. Last one that I'm trying to use is this: </p>
  
  <pre><code>var collection = mongoDbServer.GetCollection&lt;BsonDocument&gt;("post");
          var filter = Builders&lt;PostInfo&gt;.Filter.Eq(e =&gt; e._id, temp[0]);
  
          var update = Builders&lt;PostInfo&gt;.Update.Push&lt;string&gt;(e =&gt; e.Comments, temp[1]);
          await collection.FindOneAndUpdateAsync(filter, update);
  </code></pre>
  
  <p>But there is error in "FindOneAndUpdateAsync". Am I doing something wrong? I would appreciate any help.</p>