title: appending to rake db:seed in rails and running it without duplicating data
body: <p>Rake db:seed populates your db with default database values for an app right? So what if you already have a seed and you need to add to it(you add a new feature that requires the seed). In my experience, when I ran rake db:seed again, it added the existing content already so existing content became double.</p>
  
  <p>What I need is to add some seeds and when ran, it should just add the newest ones, and ignore the existing seeds. How do I go about with this? (the dirty, noob way I usually do it is to truncate my whole db then run seed again, but that's not very smart to do in production, right?)</p>