Check for pending Django migrations

Question

In Django, is there an easy way to check whether all database migrations have been run? I've found manage.py migrate --list, which gives me the information I want, but the format isn't very machine readable.

For context: I have a script that shouldn't start running until the database has been migrated. For various reasons, it would be tricky to send a signal from the process that's running the migrations. So I'd like to have my script periodically check the database to see if all the migrations have run.

Answer 1

Shell

The only simple solution I've found so far is running

./manage.py showmigrations | grep '\[ \]' 

which will output an empty string in case all migrations have been applied.

However, it is closely tied to the output format.

Python

I checked the source code of migrate command and it seems like this should do the trick:

from django.db.migrations.executor import MigrationExecutor from django.db import connections, DEFAULT_DB_ALIAS   def is_database_synchronized(database):     connection = connections[database]     connection.prepare_database()     executor = MigrationExecutor(connection)     targets = executor.loader.graph.leaf_nodes()     return not executor.migration_plan(targets)  # Usage example. if is_database_synchronized(DEFAULT_DB_ALIAS):     # All migrations have been applied.     pass else:     # Unapplied migrations found.     pass 

Answer 2

1.10 release notes:

The new makemigrations --check option makes the command exit with a non-zero status when model changes without migrations are detected.

If you don't want to create the migrations, combine it with --dry-run:

python manage.py makemigrations --check --dry-run 

Note that this doesn't check whether the migrations were applied, it only checks whether the migration files were created.