Allow empty order numbers in django admin for Entitlements

common/djangoapps/entitlements/migrations/0012_allow_blank_order_number_values.py

@@ -0,0 +1,25 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.25 on 2019-10-23 15:47
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('entitlements', '0011_historicalcourseentitlement'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='courseentitlement',
+            name='order_number',
+            field=models.CharField(blank=True, max_length=128, null=True),
+        ),
+        migrations.AlterField(
+            model_name='historicalcourseentitlement',
+            name='order_number',
+            field=models.CharField(blank=True, max_length=128, null=True),
+        ),
+    ]

common/djangoapps/entitlements/models.py

@@ -172,7 +172,7 @@ class CourseEntitlement(TimeStampedModel):
         blank=True,
         on_delete=models.CASCADE,
     )
-    order_number = models.CharField(max_length=128, null=True)
+    order_number = models.CharField(max_length=128, null=True, blank=True)
     refund_locked = models.BooleanField(default=False)
     _policy = models.ForeignKey(CourseEntitlementPolicy, null=True, blank=True, on_delete=models.CASCADE)
 
@@ -449,6 +449,14 @@ class CourseEntitlement(TimeStampedModel):
             # Force Transaction reset with an Integrity error exception, this will revert all previous transactions
             raise IntegrityError
 
+    def save(self, *args, **kwargs):
+        """
+        Null out empty strings in order_number
+        """
+        if not self.order_number:
+            self.order_number = None
+        super(CourseEntitlement, self).save(*args, **kwargs)
+
 
 @python_2_unicode_compatible
 class CourseEntitlementSupportDetail(TimeStampedModel):