Bug 1182464 - Add BigAutoField to handle big integers as primary keys

treeherder/model/fields.py

@@ -0,0 +1,32 @@
+from django.db import models
+
+
+# Django doesn't support big auto fields out of the box, see
+# https://code.djangoproject.com/ticket/14286.
+# This is a stripped down version of the BoundedBigAutoField from Sentry.
+class BigAutoField(models.AutoField):
+    description = "Big Integer"
+
+    def db_type(self, connection):
+        engine = connection.settings_dict['ENGINE']
+        if 'mysql' in engine:
+            return "bigint AUTO_INCREMENT"
+        elif 'postgres' in engine:
+            return "bigserial"
+        else:
+            raise NotImplemented
+
+    def get_related_db_type(self, connection):
+        return models.BigIntegerField().db_type(connection)
+
+    def get_internal_type(self):
+        return "BigIntegerField"
+
+
+class FlexibleForeignKey(models.ForeignKey):
+    def db_type(self, connection):
+        # This is required to support BigAutoField
+        rel_field = self.related_field
+        if hasattr(rel_field, 'get_related_db_type'):
+            return rel_field.get_related_db_type(connection)
+        return super(FlexibleForeignKey, self).db_type(connection)