makemigrations and migrate commands in Django - Step-by-Step Execution

Concept Flow - makemigrations and migrate commands

Write or change models.py

↓

Run: python manage.py makemigrations

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Create migration files

↓

Run: python manage.py migrate

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Apply migrations to database

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Database schema updated

This flow shows how changes in Django models create migration files, which are then applied to update the database schema.

Execution Sample

Django

python manage.py makemigrations
python manage.py migrate

These commands create migration files from model changes and apply them to the database.

Execution Table

Step	Command	Action	Result
1	makemigrations	Detect changes in models.py	Creates new migration file(s)
2	makemigrations	No changes detected	No new migration files created
3	migrate	Apply all unapplied migrations	Database schema updated
4	migrate	No unapplied migrations	No changes to database
5	Exit	All migrations applied	Database is up to date

💡 No more migrations to apply, database schema matches models

Variable Tracker

Variable	Start	After makemigrations 1	After migrate 1	Final
migration_files	[]	[0001_initial.py]	[0001_initial.py]	[0001_initial.py]
database_schema	empty	empty	updated with new tables	updated with new tables
models.py	defined models	defined models	defined models	defined models

Key Moments - 3 Insights

Why does running 'makemigrations' sometimes create no new files?

Because no changes were made to models.py since the last migration, as shown in execution_table step 2.

What happens if you run 'migrate' without any new migration files?

No changes are applied to the database since all migrations are already applied, as shown in execution_table step 4.

Why do we need to run both 'makemigrations' and 'migrate'?

'makemigrations' creates migration files from model changes, and 'migrate' applies those files to update the database, shown in steps 1 and 3.

Visual Quiz - 3 Questions

Look at the execution table, what is created after running 'makemigrations' when models change?

A Database schema updated

B New migration file(s)

C No changes

D Models.py file

💡 Hint

Refer to execution_table row 1 where makemigrations creates migration files

At which step does the database schema get updated?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look at execution_table row 3 where migrate applies migrations

If you change models.py but forget to run 'makemigrations', what happens when you run 'migrate'?

A No migration files to apply, so no database change

B Database updates with new schema

C Error occurs

D New migration files are created automatically

💡 Hint

Check variable_tracker and execution_table steps 1 and 3 for migration file creation and application

Concept Snapshot

Django migrations update your database schema.
Run 'makemigrations' to create migration files from model changes.
Run 'migrate' to apply these files to the database.
No model changes means no new migration files.
Migrations keep your database and models in sync.

Full Transcript

In Django, when you change your models.py file, you need to update your database schema to match. First, you run 'python manage.py makemigrations' which looks at your models and creates migration files describing the changes. If no changes are found, no new files are created. Next, you run 'python manage.py migrate' which applies all pending migration files to the database, updating its structure. If there are no new migrations, the database stays the same. This two-step process ensures your database matches your code models.