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Code Issues 16 Releases Wiki Activity

Made a few cosmetic updates to "Migrations that add unique fields".

This commit is contained in:
Paolo Melchiorre 2017-03-27 20:07:11 +02:00 committed by Tim Graham
parent ed0cbc8d8b
commit 24d53786d4
1 changed files with 5 additions and 5 deletions
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10
docs/howto/writing-migrations.txt
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@ -94,8 +94,8 @@ the respective field according to your needs.
give them meaningful names in the examples below.
* Copy the ``AddField`` operation from the auto-generated migration (the first
of the three new files) to the last migration and change ``AddField`` to
``AlterField``. For example:
of the three new files) to the last migration, change ``AddField`` to
``AlterField``, and add imports of ``uuid`` and ``models``. For example:
.. snippet::
:filename: 0006_remove_uuid_null.py
@ -104,7 +104,6 @@ the respective field according to your needs.
from django.db import migrations, models
import uuid
class Migration(migrations.Migration):
dependencies = [
@ -146,7 +145,8 @@ the respective field according to your needs.
* In the first empty migration file, add a
:class:`~django.db.migrations.operations.RunPython` or
:class:`~django.db.migrations.operations.RunSQL` operation to generate a
unique value (UUID in the example) for each existing row. For example:
unique value (UUID in the example) for each existing row. Also add an import
of ``uuid``. For example:
.. snippet::
:filename: 0005_populate_uuid_values.py
@ -159,7 +159,7 @@ the respective field according to your needs.
MyModel = apps.get_model('myapp', 'MyModel')
for row in MyModel.objects.all():
row.uuid = uuid.uuid4()
row.save()
row.save(update_fields=['uuid'])
class Migration(migrations.Migration):