Add constraints

things/migrations/0007_auto_20170902_1035.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.1 on 2017-09-02 08:35
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+ dependencies = [
+ ('things', '0006_auto_20170529_1707'),
+ ]
+
+ operations = [
+ migrations.AlterField(
+ model_name='category',
+ name='parent',
+ field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.CASCADE, to='things.Category', verbose_name='the parent category'),
+ ),
+ ]

things/migrations/0008_auto_20170902_1059.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.1 on 2017-09-02 08:59
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+ dependencies = [
+ ('things', '0007_auto_20170902_1035'),
+ ]
+
+ operations = [
+ migrations.AlterField(
+ model_name='category',
+ name='parent',
+ field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, to='things.Category', verbose_name='the parent category'),
+ ),
+ ]

things/migrations/0009_auto_20170902_1119.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.1 on 2017-09-02 09:19
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+ dependencies = [
+ ('things', '0008_auto_20170902_1059'),
+ ]
+
+ operations = [
+ migrations.AlterField(
+ model_name='state',
+ name='id',
+ field=models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID'),
+ ),
+ ]

things/migrations/0010_auto_20170902_1714.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.1 on 2017-09-02 15:14
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+ dependencies = [
+ ('things', '0009_auto_20170902_1119'),
+ ]
+
+ operations = [
+ migrations.AlterField(
+ model_name='thing',
+ name='expiry_date',
+ field=models.DateField(blank=True, null=True),
+ ),
+ migrations.AlterField(
+ model_name='thing',
+ name='location',
+ field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, to='locations.Location'),
+ ),
+ migrations.AlterField(
+ model_name='thing',
+ name='parent',
+ field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to='things.Thing', verbose_name='contained inside of'),
+ ),
+ migrations.AlterField(
+ model_name='thing',
+ name='quantity',
+ field=models.FloatField(blank=True, null=True),
+ ),
+ ]

things/models.py

@@ -16,11 +16,10 @@ class Category(models.Model):
 
  name = models.CharField(max_length=80, null=False, unique=True)
  description = models.TextField()
- parent = models.ForeignKey('self', verbose_name='the parent category')
+ parent = models.ForeignKey('self', verbose_name='the parent category', blank=True, null=True)
 
 
 class State(models.Model):
- id = models.IntegerField(primary_key=True)
  name = models.CharField(max_length=80)
  description = models.TextField()
 
@@ -35,22 +34,23 @@ class Thing(models.Model):
  description = models.TextField()
  categories = models.ManyToManyField(Category)
 
- quantity = models.FloatField(null=True)
+ quantity = models.FloatField(null=True, blank=True)
 
  consumable = models.BooleanField(default=False)
  borrowable = models.BooleanField(default=False)
  private = models.BooleanField(default=False)
 
- location = models.ForeignKey(Location, null=True)
+ location = models.ForeignKey(Location, null=True, blank=True)
  parent = models.ForeignKey('self',
  verbose_name='contained inside of',
  on_delete=models.SET_NULL,
- null=True)
+ null=True,
+ blank=True)
 
  owner = models.ForeignKey(User, verbose_name='owner of the thing')
  state = models.ForeignKey(State)
  metadata = JSONField()
- expiry_date = models.DateField()
+ expiry_date = models.DateField(null=True, blank=True)
 
  def clean(self):
  if self.location and self.parent: