title: How to design to save a field of a aggregate root in DDD
body: <p>I learned DDD recently, we used to encapsulate the creation, update, deletion in to the repository to persist the changes to the DB. </p>
  
  <p>With ORM tools, we can ignore the detail of the persistence, usually the argument of the repository is an aggregate root object, and the ORM execute the conversion of the persistence(for example, it will update one field if there just one change).</p>
  
  <p>But if without ORM, there is just a field of the aggregate root object changed and save it to DB, how to design this for repository? support a method to save this field? There is a method called update to save all properties, but with it, it will cause performance issue.</p>