title: How to perform partial update with Spring data mongoDB(MongoOperations)
body: <p>In my database I have a document that looks like this </p>
  
  <pre><code>{
      "_id" : ObjectId("5864ddd8e38112fd70b89893"),
      "_class" : "com.apic.models.UserReg",
      "name" : "Bijay",
      "email" : "apic.apps@gmail.com",
      "psd" : "16d932a5a3da90cc6afd831016b5a6821f0badf7e2c624159205924433613c3a",
      "activationToken" : "fe8376ea2dbdf61ebc0f11a2361d741ba3178362d5bf876cf47e6a126bc5b39c",
      "verified" : false
  }
  </code></pre>
  
  <p>I also have a bean that looks like this </p>
  
  <pre><code>public class User {
    @Id
    private int id;
    private String name;
    private String email;
  
    // getter/setter methods
  
  }
  </code></pre>
  
  <p>So when I try to call <code>save()</code> method of <code>MongoOperations</code>, it replaces all missing properties like psd, verified and activationToken. </p>
  
  <pre><code>mongoOperations.save(user, COLLECTION);
  </code></pre>
  
  <p>Is there any way where I can update only the existing properties in my models class and leave others as it is?</p>