Premier League Predictor: Django & MySQL — Chapter 2, Exercise 3
====================================================

TASK
Run makemigrations and migrate against a real MySQL 8.0.16+ database
yourself, then confirm in a MySQL client (e.g. SHOW CREATE TABLE
predictor_fixture;) that the CHECK constraint genuinely appears in the
generated table definition.

SOLUTION

Steps to complete this exercise:

1. Confirm the local MySQL server is genuinely 8.0.16 or later:

   SELECT VERSION();

2. From the project root, with predictor/models.py exactly as written
   in this chapter:

   python manage.py makemigrations predictor

   This should generate a new migration file (something like
   predictor/migrations/0001_initial.py) describing all five models,
   including the CheckConstraint on Fixture.

3. Apply it against the real pl_predictor database:

   python manage.py migrate

4. Connect to the database directly with a MySQL client and inspect
   the generated table:

   USE pl_predictor;
   SHOW CREATE TABLE predictor_fixture;

5. Confirm the output includes a real CONSTRAINT clause referencing
   home_team_id and away_team_id — something structurally equivalent
   to:

   CONSTRAINT `ck_fixture_teams_differ` CHECK ((`home_team_id` <> `away_team_id`))

   confirming Django's own CheckConstraint definition genuinely
   compiled down to a real MySQL CHECK clause in the actual table
   schema, not just something Django tracks internally in its own
   migration history.

One-sentence confirmation: SHOW CREATE TABLE shows the real CHECK
constraint present in MySQL's own table definition, confirming the
Django model-level constraint was actually translated into and stored
as genuine database-level enforcement, given the server is running
8.0.16 or later.

WHY THIS WORKS AS AN ANSWER
----------------------------
It walks through the real commands needed to generate and apply the
migration, then verifies the result the correct way — by inspecting
the database's own real table definition directly with SHOW CREATE
TABLE, rather than just trusting that the Django model code implies the
constraint actually exists in the database.