Models are the way that Rails connects to the database. The model is a Class which maps to it's name, plural as a table. Tweet.find(id) will look in the Tweets table by default.

Validates

In the model, you can make sure that an attribute validates.

validates :attribute, :presence => true - will not save the record without :attribute

validates :attribute, :numericality => true - will only save a number

validates :attribute, :uniqueness => true - so there are no dupes

validates :password, :confirmation => true

validates :password, :length => {:minimum => 3, :maximum => 100}

validates_format_of :email, :with => /regex/i

validates_inclusion_of :age, :in => 21..99

validate_exclusion_of :age, :in => 0..21, :message => "Sorry, you must be 21"

Relationships

This is how tables connect. Not yet sure how to decide when to build a new table. Tables can belong to another table, or have instances of another table. Inside of the model - belongs_to :zombie or has_many :tweets

Setting up relationships allows you to call data easier from the counsel.

t = Tweet.find(1) t.zombie >>>> will return the zombie that the tweet belongs to.