boards/migrations/0065_attachmentsticker.py

# -*- coding: utf-8 -*-
# Generated by Django 1.11 on 2017-10-14 13:25
from __future__ import unicode_literals

from django.db import migrations, models
import django.db.models.deletion
from django.db.models import Q


class Migration(migrations.Migration):

    dependencies = [
        ('boards', '0064_remove_post_version'),
    ]

    def attachment_alias_to_sticker(apps, schema_editor):
        Attachment = apps.get_model('boards', 'Attachment')
        AttachmentSticker = apps.get_model('boards', 'AttachmentSticker')

        attachments = Attachment.objects.exclude(Q(alias=None) | Q(alias=''))
        for attachment in attachments:
            AttachmentSticker.objects.create(attachment=attachment,
                                             name=attachment.alias)

    operations = [
        migrations.CreateModel(
            name='AttachmentSticker',
            fields=[
                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                ('name', models.TextField(unique=True)),
                ('attachment', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='boards.Attachment')),
            ],
        ),
        migrations.RunPython(attachment_alias_to_sticker),
        migrations.RemoveField(
            model_name='Attachment',
            name='alias',
        )
    ]