Fixed model checks.

Author: jackton1

migrations/0001_initial.py

@@ -43,7 +43,7 @@ class Migration(migrations.Migration):
                         "active",
                         models.NullBooleanField(),
                     )
-                    if django.VERSION < (3, 2)
+                    if django.VERSION < (2, 1)
                     else (
                         "active",
                         models.BooleanField(null=True),

models.py

@@ -1,3 +1,4 @@
+import django
 from django.db import models
 from django.utils.translation import gettext_lazy as _
 
@@ -7,7 +8,11 @@ class TestModel(models.Model):
     update_at = models.DateTimeField(auto_now=True)
     name = models.CharField(max_length=500)
     age = models.PositiveIntegerField(default=50)
-    active = models.BooleanField(null=True)
+
+    if django.VERSION < (2, 1):
+        active = models.NullBooleanField()
+    else:
+        active = models.BooleanField(null=True)
 
     class Meta:
         verbose_name = _("test model")