Active Data provides a way for Ruby objects to connect with relational database tables and allows for associations between different class models.

Objects created using Active Data will inherit from a SQLObject class and use strict naming conventions to directly tie that class model to a table of the same name. For example, a Cat object will relate to a table named cats.

• Two models can relate by a has_many or belongs_to association:

class Guitar < SQLObject
  belongs_to :musician
end

class Musician < SQLObject
  has_many :guitars
  belongs_to :band
end

class Band < SQLObject
  has_many :musicians
end

• Running Musician.first.guitars will take the first Musician from the musicians table and return a list of Guitar objects that are owned by that Musician.

• ::all - Returns a list of every row in a particular table
• ::columns - Returns a list of each column name in a particular table
• ::finalize! - Creates setter and getter methods for each table column:

  Band.finalize!
  Band.columns # => [:id, :name]
  b = Band.new
  b.name = "Radiohead"
  b.name #=> "Radiohead"

• ::find(id) - Fetches a row with a matching id and returns a new object
• ::first, ::last - Returns the first or last row in a table as a new object

• #attributes - Returns a hash of attributes for a given instance
• #attribute_values - Returns an array of attribute values
• #insert - Creates a new row in the data table for a given instance
• #update - Updates the row in the data table that matches the given id
• #save - Calls either insert or update based on the object's current status in the database

• #where - The SQLObject class extends the Searchable module and uses where to search the database for specific values

  Band.where( { name: "Radiohead" } )
  #=> [#<Band:0x007ff8d373a248 @attributes={:id=>3, :name=>"Radiohead"}>]