Flask-SQLAlchemy Validations Lab

Learning Goals

  • Define validations in data processing.
  • Ensure that only acceptable input is sent to the database using validations.

Key Vocab

  • Constraint: a rule enforced on the data columns of a table. Ensures that only appropriate data is saved to the database.
  • Validation: an automatic check to ensure that data entered is sensible and feasible.
  • Forms: A web form (or HTML form) is a place where users enter data or personal information that's then sent to a server for processing.

Introduction

This is a test-driven lab.

Run pipenv install to create your virtual environment and pipenv shell to enter the virtual environment.

pipenv install && pipenv shell

This project has starter code for a couple of models, Author and Post. To get create the database from the initial migration, run:

$ cd server
$ flask db upgrade
$ python seed.py

Basic Validations

Add validators to the Author and Post models such that:

  1. All authors have a name.
  2. No two authors have the same name.
  3. Author phone numbers are exactly ten digits.
  4. Post content is at least 250 characters long.
  5. Post summary is a maximum of 250 characters.
  6. Post category is either Fiction or Non-Fiction.
  7. Post title is sufficiently clickbait-y and must contain one of the following:
    • "Won't Believe"
    • "Secret"
    • "Top"
    • "Guess"

You should not need to run another migration, unless you altered model constraints.

Run pytest -x to run your tests. Use these instructions and pytest's error messages to complete your work in the server/ folder.


Resources