ORM example

orm.rb

class ORM
    def save
        table_name = self.class

        instance_variable_names = self.instance_variables.map do |i|
            i.slice(1, i.length)
        end

        instance_variable_values = self.instance_variables.map do |i|
            self.instance_variable_get("#{i}")
        end

        if self.id == nil
            sql_columns = instance_variable_names.join(', ')

            sql_values_arr = []
            self.instance_variables.each do |i|
                sql_values_arr << '"' << self.instance_variable_get("#{i}") << '"'
            end
            sql_values = sql_values_arr.join(", ")

            sql_command = "INSERT INTO #{table_name}
                (#{sql_columns})
                VALUES
                (#{sql_values})"
        else
            components = []
            instance_variable_names.each do |ivn|
                value = self.instance_variable_get("@#{ivn}")
                component = "#{ivn}='#{value}'"
                components << component
            end
            components_string = components.join(', ')
            query = "UPDATE #{table_name} SET #{components_string}"
        end
    end
end

class User < ORM
    attr_accessor :id, :name, :email, :phone

    def initialize(name, email, phone, gender, id=nil)
        @id = id
        @name = name
        @email = email
        @phone = phone
        @gender = gender
    end

end

class Dog < ORM
    attr_accessor :num_legs, :personality_type, :bark_pitch
end

dog = Dog.new
dog.num_legs = 3
dog.personality_type = 'evil'
dog.bark_pitch = 'high pitched'
puts dog.save

murat = User.new("murat", "[email protected]", "1234234", "doesnt matter in this day and age")
puts murat.save