So about a year ago I started a project and like all new developers I didn't really focus too much on the structure, however now I am further along with Django it has started to appear that my project layout mainly my models are horrible in structure.
I have models mainly held in a single app and really most of these models should be in their own individual apps, I did try and resolve this and move them with south however I found it tricky and really difficult due to foreign keys ect.
However due to Django 1.7 and built in support for migrations is there a better way to do this now?
This can be done fairly easily using migrations.SeparateDatabaseAndState
. Basically, we use a database operation to rename the table concurrently with two state operations to remove the model from one app's history and create it in another's.
python manage.py makemigrations old_app --empty
In the migration:
class Migration(migrations.Migration):
dependencies = []
database_operations = [
migrations.AlterModelTable('TheModel', 'newapp_themodel')
]
state_operations = [
migrations.DeleteModel('TheModel')
]
operations = [
migrations.SeparateDatabaseAndState(
database_operations=database_operations,
state_operations=state_operations)
]
First, copy the model to the new app's model.py, then:
python manage.py makemigrations new_app
This will generate a migration with a naive CreateModel
operation as the sole operation. Wrap that in a SeparateDatabaseAndState
operation such that we don't try to recreate the table. Also include the prior migration as a dependency:
class Migration(migrations.Migration):
dependencies = [
('old_app', 'above_migration')
]
state_operations = [
migrations.CreateModel(
name='TheModel',
fields=[
('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
],
options={
'db_table': 'newapp_themodel',
},
bases=(models.Model,),
)
]
operations = [
migrations.SeparateDatabaseAndState(state_operations=state_operations)
]