Challenge 3: Explore manage.py — Possible Solution
====================================================================

$ python manage.py help

# (abbreviated — the real output lists many more, grouped by app)
#
# [django]
#     check
#     dbshell
#     diffsettings
#     makemigrations
#     migrate
#     runserver
#     shell
#     showmigrations
#     startapp
#     startproject
#     test

THREE SUBCOMMANDS, EXPLAINED
-----------------------------

1. python manage.py shell
   Opens an interactive Python REPL with Django already configured and
   your project's settings loaded — meaning you can immediately import
   and query your own models (e.g. `from catalog.models import Book;
   Book.objects.all()`) without manually setting up Django first. Reach
   for this when you want to quickly inspect or manipulate real data
   without writing a throwaway script or view.

2. python manage.py dbshell
   Drops you into your database's own native command-line client
   (psql for PostgreSQL, the sqlite3 CLI for SQLite, etc.), already
   connected to the project's configured database — no need to look up
   or type the connection string yourself. Reach for this when you want
   to run a raw SQL query directly, outside of anything Django's ORM
   would generate.

3. python manage.py showmigrations
   Lists every app's migrations and marks which ones have actually been
   applied to the current database ([X]) versus which are still pending
   ([ ]). Reach for this when `migrate` behaves unexpectedly, or before
   deploying, to confirm the database is in the state your code expects.

WHY THIS WORKS
--------------
- manage.py help surfaces Django's own built-in commands grouped by the
  app that defines them (most of the ones above come from "django" core
  itself, but a third-party app or your own app can register additional
  subcommands the same way) — this is the fastest way to discover what's
  available without searching documentation first.
- Each command exists because Django assumes certain tasks are common
  enough across nearly every project (inspecting data, running raw SQL,
  checking migration state) that they deserve a first-class command
  rather than requiring a hand-written script — another small instance of
  the "batteries included" theme from this chapter.
- Building the habit of running `manage.py help` when unsure what's
  available (rather than only learning commands one at a time as
  tutorials mention them) pays off as Django projects grow more complex.