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docs/migrations.md

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+# Migrations
+
+OhMyAPI uses [Aerich](https://github.com/tortoise/aerich) - a database migrations tool for TortoiseORM.
+
+## Making migrations
+
+Whenever you add, remove or change fields of a database model, you need to create a migration for the change.
+
+```
+ohmyapi makemigrations [ <app> ]  # no app indicates all INSTALLED_APPS
+```
+
+This will create a `migrations/` directory with subdirectories for each of your apps.
+
+## Migrating
+
+When the migrations are create, they need to be applied:
+
+```
+ohmyapi migrate [ <app> ]  # no app indicates all INSTALLED_APPS
+```
+