title: Is it possible to validate model instance with Sequelize before saving it using model constraints?
body: <p>I need to validate model instance before saving it in the database. I was thinking <a href="http://docs.sequelizejs.com/class/lib/model.js~Model.html#static-method-build" rel="nofollow noreferrer">Model build</a> method might be of a use, but it's not. Constraints and types are not checked, so if I'm, for instance, trying to save a string in an integer field, that passes.</p>
  
  <p>I guess I wouldn't be able to check <code>unique</code> and <code>foreign key</code> constraints because of different validation and saving times, but that's OK.</p>