Active Record Lite

An ORM inspired by Rails' Active Record and designed with Ruby RSPEC to ensure test-driven development.

Features

Easy, English-like SQL queries using associations
Quick, clean getter and setter methods through 'attr_accessor':

class AttrAccessorObject
  def self.my_attr_accessor(*names)
    names.each do |name|
      define_method("#{name}=") do |value|
        ivar_name = "@#{name}"
        instance_variable_set(ivar_name, value)
      end
    end

    names.each do |name|
      define_method("#{name}") do
        getter_ivar_name = "@#{name}"
        instance_variable_get(getter_ivar_name)
      end
    end
  end
end

Use of Rails' 'has_many', 'belongs_to', and 'has_one_through' associations

module Associatable
  def belongs_to(name, options = {})
    self.assoc_options[name] = BelongsToOptions.new(name, options)

    define_method(name) do
      options = self.class.assoc_options[name]

      key_val = self.send(options.foreign_key)
      options
        .model_class
        .where(options.primary_key => key_val)
        .first
    end
  end

  def has_many(name, options = {})
    self.assoc_options[name] =
      HasManyOptions.new(name, self.name, options)

    define_method(name) do
      options = self.class.assoc_options[name]

      key_val = self.send(options.primary_key)
      options
        .model_class
        .where(options.foreign_key => key_val)
    end
  end

  def assoc_options
    @assoc_options ||= {}
    @assoc_options
  end
end

Ability to save and update models by utilizing SQL within a ruby code base

def update
  col_names = self.class.columns.map { |col| "#{col} = ?" }.join(', ')
  DBConnection.execute(<<-SQL, *attribute_values, self.id)
    UPDATE
      #{self.class.table_name}
    SET
      #{col_names}
    WHERE
      id = ?
  SQL
end

josephwilliams/Active_Record_Lite

Active Record Lite

Features