title: how set default value of db in ruby on rails
body: <p>i was wondering to set default value when we type command for model, i.e </p>
  
  <p>rails g model admin user:string password:string</p>
  
  <p>how i can set default value to user and pass "admin"</p>
  
  <p>something like. </p>
  
  <p>rails g model admin user:string default:"admin" password:string default:"admin"</p>
  
  <p>Thanks</p>