Data Binge

Data Binge is an Object Relational Mapping (ORM) tool, and it is based on Active Record. It is used to make database manipulations easy and painless by using a class for each table which can effortlessly translate information from the database into easily-manipulatable objects. These classes, or models, enable an easy interface for users to get, set, and change data without ever having to directly access the database. Model classes are also easily linked to each other through a process of setting a single foreign_key in the database and then appropriately describing the relation as a function name. Data Binge does all the heavy lifting, as long as the user sticks closely to the suggested naming convention.

In order to understand the relationship between tables, models, associations, etc. A few rules must be followed. By using the naming scheme provided, certain default values can be inferred and make configuration a breeze. Say goodbye to boilerplate!

Getting Started

• Download the zip or clone the root directory into your working folder.

Using the provided DB

If you'd like to play around first with the test file, open up pry and load the test file load 'lib/test.rb' and start making some queries like Driver.first.cars or Car.first.driver.

Using your own DB

• Change the paths in db/db_connection.rb to point to your database files.

SQL_FILE = File.join(ROOT_FOLDER, 'cars.sql') # Change 'cars.sql' to your sql file
DB_File = File.join(ROOT_FOLDER, 'cars.db')   # Change 'cars.db' to your db file

• Require DataBinge/lib/data_binge into your model files, and define your classes to inherit from DataBinge.

require_relative 'data_binge'

class Car < DataBinge
end

• Call the class method finalize! in order to define instance getter/setter methods related to column names.

Car.finalize!
=> [:id, :model, :owner_id] # Car DB columns

There is a test file included to show how to set up a model with associations.

Reminder: The instance variables initialized by finalize! are the column names declared in the database that have been setup in the sql file. Make sure to call finalize! on your model to initialize the class accessors to get/set entry column values.

API

##Public Class Methods

::columns Returns an array of table columns in symbol format of the specified DataBinge class.

  class Car < DataBinge
  end

  Car.columns
=> [:id, :model, :owner_id]

::finalize! Creates attribute accessor methods for each column field

Car.finalize!
# id
# model
# owner_id

::table_name=(name) Sets a class instance variable to the name specified. This is the table name used for SQL querying.

Car.table_name = "cars"
# self.table_name => cars

::table_name Gets the class table name

Car.table_name
=> "cars"

::all Returns all rows from the class' table

Driver.all
=> [#<Driver:0x007f90f39323e0
  @attributes={:id=>1, :fname=>"Michael", :lname=>"Carillo", :garage_id=>1}>,
 #<Driver:0x007f90f3932200
  @attributes={:id=>2, :fname=>"Laura", :lname=>"Carillo", :garage_id=>1}>,
 #<Driver:0x007f90f3932020
  @attributes={:id=>3, :fname=>"Ryan", :lname=>"Denning", :garage_id=>2}>,
 #<Driver:0x007f90f3931e40
  @attributes={:id=>4, :fname=>"Carlos", :lname=>"Varjano", :garage_id=>nil}>]

::find(id) Queries the database for a record with id => id

Garage.find(2)
=> #<Garage:0x007fd7e20f5610 @attributes={:id=>2, :address=>"Vance and McGilbert"}>

::first Selects the first record in the table

Garage.first
=> #<Garage:0x007fd7e3850cd8 @attributes={:id=>1, :address=>"7th and Columbia"}>

Public Instance Methods

#attributes Returns the current values for the row object

kyle.attributes
=> {:fname=>"Kyle", :lname=>"Berg", :garage_id=>3, :id=>5}

#insert Inserts the current object into the database and creates a new row. Returns the id of the new object.

kyle.insert
=> 5

Driver.find(5)
=> #<Driver:0x007fd7e39b4818 @attributes={:id=>5, :fname=>"Kyle", :lname=>"Berg", :garage_id=>3}>

#update Overwrites the row attributes of the DataBinge object in the database.

kyle
=> #<Driver:0x007fd7e2191b50 @attributes={:fname=>"Kyle", :lname=>"Berg", :garage_id=>3, :id=>5}>
[13] pry(main)> kyle.lname = "Maroney"
=> "Maroney"
[14] pry(main)> kyle.garage_id = 2
=> 2
[15] pry(main)> kyle.update
=> #<Driver:0x007fd7e2191b50 @attributes={:fname=>"Kyle", :lname=>"Maroney", :garage_id=>2, :id=>5}>
Driver.find(5)
=> #<Driver:0x007fbba29fc8a0 @attributes={:id=>5, :fname=>"Kyle", :lname=>"Maroney", :garage_id=>2}>

#save If the object has no id, save will insert. Otherwise, save will update.

Kayla = Driver.new(fname: "Kayla", lname: "Porro", garage_id: 6)
=> #<Driver:0x007fe1e4162600 @attributes={:fname=>"Kayla", :lname=>"Porro", :garage_id=>6}>
Kayla.save
=> #<Driver:0x007fe1e4162600 @attributes={:fname=>"Kayla", :lname=>"Porro", :garage_id=>6, :id=>5}>

Kayla.garage_id = 5
=> 5
Kayla.save
=> #<Driver:0x007fe1e4162600 @attributes={:fname=>"Kayla", :lname=>"Porro", :garage_id=>5, :id=>5}>

Associations

• Tables link together through foreign keys

class Car < DataBinge
  belongs_to(
    :driver,
    foreign_key: :owner_id
  )
end

mustang.driver
# => #<Driver:0x007f95d39560d0 @attributes={:id=>1, :fname=>"Michael", :lname=>"Carillo", :garage_id=>1}>

Notice that the method name and foreign key are different, therefore requiring an explicit foreign key definition. However, the method name :owner matches up to the class name, :owner_id, and is implicitly inferred.

• Association with full inference

class Driver < DataBinge
  belongs_to :garage
end

Driver.first.garage
# => #<Garage:0x007f95d21f96a8 @attributes={:id=>1, :address=>"7th and Columbia"}>

• has_many_through associations

class Garage < DataBinge
  has_many_through(
    :cars,
    :drivers,
    :cars
  )
end

Garage.first.cars
# => [#<Car:0x007f95d3a508f0 @attributes={:id=>1, :model=>"Mustang Shelby", :owner_id=>1}>,
      #<Car:0x007f95d3a4ba30 @attributes={:id=>2, :model=>"Toyota Camry", :owner_id=>2}>]