Initial entry of models

project_directory/common/models.py

@@ -0,0 +1,22 @@
+from django.db import models
+
+
+class CommonInfo(models.Model):
+    name = models.CharField(max_length=100)
+    active = models.BooleanField(default=True)
+
+    def __unicode__(self):
+        return self.name
+
+    class Meta:
+        abstract = True
+
+
+class Category(CommonInfo):
+    parent = models.ForeignKey('self', blank=True, null=True,
+                               on_delete=models.SET_NULL)
+
+
+class Sample(CommonInfo):
+    parent = models.ForeignKey(Category, blank=True, null=True,
+                               on_delete=models.SET_NULL)