title: Relationships by _id in MongoDB
body: <p>I have been studying MongoDb to migrate my project to <code>MEAN</code> technologies and I have in my database two collections <code>person</code> where I put all basic information like name, age, etc and <code>account</code> where I put information like email, pass, level. I need to create a relationship between that collections. What I did was set <code>account</code>'s _id equals to <code>person</code>' _id. Is that correct ?</p>
  
  <p>Person Collection</p>
  
  <pre><code>{
      "_id" : ObjectId("569c39684e23c75303a0fe32"),
      "name" : {
              "First" : "Daniel Alessandro",
              "Last" : "Aguilar Chombo"
      },
      "area" : 1
  }
  </code></pre>
  
  <p>Account Collection</p>
  
  <pre><code>{
          "_id" : ObjectId("569c39684e23c75303a0fe32"),
          "email" : "testAccount@live.com",
          "password" : "testPassword4218",
          "level" : 0
  }
  </code></pre>