Generate Django Database Migrations

Commands

Generate migrations automatically based on model changes:

sentry django makemigrations

For a specific app:

sentry django makemigrations <app_name>

Generate an empty migration (for data migrations or custom work):

sentry django makemigrations <app_name> --empty

After Generating

1. If you added a new model, ensure it's imported in the app's

   __init__.py

2. Review the generated migration for correctness
3. Run

   sentry django sqlmigrate <app_name> <migration_name>

   to verify the SQL

Guidelines

Adding Columns

• Use

  db_default=<value>

  instead of

  default=<value>

  for columns with defaults
• Nullable columns: use

  null=True

• Not null columns: must have

  db_default

  set

Adding Indexes

For large tables, set

is_post_deployment = True

on the migration as index creation may exceed the 5s timeout.

Deleting Columns

1. Make column nullable (

   null=True

   ) if not already
2. Remove all code references
3. Replace

   RemoveField

   with

   SafeRemoveField(..., deletion_action=DeletionAction.MOVE_TO_PENDING)

4. Deploy, then create second migration with

   SafeRemoveField(..., deletion_action=DeletionAction.DELETE)

Deleting Tables

1. Remove all code references
2. Replace

   DeleteModel

   with

   SafeDeleteModel(..., deletion_action=DeletionAction.MOVE_TO_PENDING)

3. Deploy, then create second migration with

   SafeDeleteModel(..., deletion_action=DeletionAction.DELETE)

Renaming Columns/Tables

Don't rename in Postgres. Use

db_column

or

Meta.db_table

to keep the old name.

Resolving Merge Conflicts

If

migrations_lockfile.txt

conflicts:

bin/update-migration <migration_name>

This renames your migration, updates dependencies, and fixes the lockfile.