title: How to change a OneToOneField into ForeignKey in django model with data in both table?
body: <p>I am having a model Employee with a OneToOneField relationship with Django USER model. Now for some reason, I want to change it to the ManyToOne(ForeignKey) relationship with the User model.
  Both these tables have data filled. Without losing the data how can I change it?
  Can I simply change the relationship and migrate?</p>