milibytes / ph3-orm-mock-coffee-shop

Phase 3 ORM Mock Challenge - Coffee Shop

For this mock challenge, we'll be working with a domain for a coffee shop.

We have two models: CoffeeOrder which shows the coffee orders which belong to a Customer.

Topics

• Classes and Instances
• Class and Instance Methods
• Variable Scope
• lists and list Methods
• SQL queries
• ORM methods

Instructions

To get started, run pipenv install while inside of this directory.

Only one of the tables, customers has been created so far. Additionally the Customer class already has its required functionality and you won't have to build additional methods for it.

Build out all of the methods listed in the deliverables for CoffeeOrder. The methods are listed in a suggested order, but you can feel free to tackle the ones you think are easiest. Be careful: some of the later methods rely on earlier ones.

We've provided you with a tool that you can use to test your code. To use it, run python debug.py from the command line. This will start a ipdb session with your classes defined. You can test out the methods that you write here. You can add code to the debug.py file to define variables and create sample instances of your objects. There are no formal tests to run with this code so be sure to test it in the debug.py often.

Writing error-free code is more important than completing all of the deliverables listed - prioritize writing methods that work over writing more methods that don't work. You should test your code in the console as you write.

Similarly, messy code that works is better than clean code that doesn't. First, prioritize getting things working. Then, if there is time at the end, refactor your code to adhere to best practices. When you encounter duplicated logic, extract it into a shared helper method.

Deliverables

Write the following methods in the classes in the files provided. Feel free to build out any helper methods if needed.

Initializers and Properties

• CoffeeOrder classmethod create_table()
  • Creates a coffee_orders table with these columns: id (INTEGER), coffee_name (TEXT), price (INTEGER), customer_id (NUMBER)
• CoffeeOrder __init__(coffee_name, price, customer_id, id=None)
  • CoffeeOrder is initialized with a coffee_name (string) and a price (integer or float)
  • When initialized a CoffeeOrder should have an id of None
  • Assume that CoffeeOrders will always be initialized with the proper data types
• CoffeeOrder __repr__()
  • Returns the CoffeeOrder instance in the format below:
  • CoffeeOrder(id={id} coffee_name={coffee_name}, price={price}, customer_id={customer_id})
• CoffeeOrder property price()
  • Returns the CoffeeOrder's price
  • The price must be an number greater than 0

SQL Methods

• CoffeeOrder create()
  • Creates a CoffeeOrder in the database with the instance's attributes
• CoffeeOrder delete()
  • Deletes the CoffeeOrder from the database
  • No return value is necessary for this method
• CoffeeOrder classmethod query_all()
  • Returns a list of CoffeeOrder instances based on rows in the database
  • The return value ought to be a list of CoffeeOrder instances
• CoffeeOrder classmethod query_by_id(id)
  • Returns a CoffeeOrder instance from the database that matches the id argument
  • The return value ought to be a CoffeeOrder instance or None if no CoffeeOrder exists with that id

Association Properties

• CoffeeOrder property customer()
  • Returns the Customer that the CoffeeOrder is associated with as an instance
  • If the CoffeeOrder is not associated with a Customer returns None
  • When setting the customer, if the argument is a Customer instance it associates the CoffeeOrder with the customer
  • The database is already seeded with customers for testing purposes
  • Customer(id=1, name="Bender")
  • Customer(id=2, name="Leela")
  • Customer(id=3, name="Phillip J Fry")

BONUS Methods

• CoffeeOrder classmethod highest_price()
  • Returns the CoffeeOrder with the highest price from the database as an instance
• Customer classmethod average_price()
  • Returns the average price of all of a customer's coffee orders
• CoffeeOrder update()
  • Updates the coffee order in the database to match any changes to the instance's attributes
• CoffeeOrder save()
  • Will either create a new entry in the database or update an existing entry for a coffee order based on whether that order has an id