create emailer version 1

env/Lib/site-packages/django/contrib/postgres/expressions.py

@@ -0,0 +1,14 @@
+from django.contrib.postgres.fields import ArrayField
+from django.db.models import Subquery
+from django.utils.functional import cached_property
+
+
+class ArraySubquery(Subquery):
+    template = "ARRAY(%(subquery)s)"
+
+    def __init__(self, queryset, **kwargs):
+        super().__init__(queryset, **kwargs)
+
+    @cached_property
+    def output_field(self):
+        return ArrayField(self.query.output_field)