title: Mongodb $in query for Array not working
body: <p>Below is the schema of document in mongo db </p>
  
  <pre><code>{
      "_id" : ObjectId("55d9a2f467d16f15a886a532"),
      "Author" : "RYTnirY",
      "Title" : "MZDCGMyXLV",
      "Content" : "HotEXFcyjaipabbAXAkKR",
      "Tags" : [ 
          "oHE,SJx,FMQ"
      ],
      "CreatedAtUtc" : ISODate("2015-08-23T10:39:48.766Z"),
      "Comments" : [ 
          {
              "Author" : "RWfSxDZ",
              "Content" : "TvYfJzLtIeaIdrxdsbQ",
              "CreatedAtUtc" : Date(-62135596800000)
          }, 
          {
              "Author" : "RFmUqfD",
              "Content" : "lHpUwrLnzXMSFtpGmo",
              "CreatedAtUtc" : Date(-62135596800000)
          }
      ]
  }
  </code></pre>
  
  <p>I want to find all documents with a specific tag for example only by oHE or oHE,SJx . I am not able to find correct query . </p>
  
  <pre><code>db.poss.find({ Tags: { $in: { [ "oHE","SJx" ] } }})
  </code></pre>