clarify UpdatedAtMixin compatiblity

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## Unreleased
 
-* Document `UpdatedAtMixin`’s incompatibility with Postgres (#1)
+* Document `UpdatedAtMixin`’s compatibility with Postgres (#1)
 
 ## 0.1.0 (2023/03/30)
 

README.md

@@ -34,5 +34,5 @@ class MyModel(Base, CreatedAtMixin):
 
 * `CreatedAtMixin`: add a `created_at` datetime field that’s automatically filled with the record’s creation date
 * `UpdatedAtMixin`: add an `updated_at` datetime field that’s automatically filled with the record’s last update date.
-  Note this doesn't work on Postgres; you have to [create a trigger](https://stackoverflow.com/a/71072370/735926).
+  Note that on Postgres this is done in Python; for a database-level update you have to [create a trigger](https://stackoverflow.com/a/71072370/735926).
 * `CreatedUpdatedAtMixin`: combined version of the previous two mixins

bixomix/dates.py

@@ -12,7 +12,8 @@ class CreatedAtMixin:
 class UpdatedAtMixin:
     """
     SQLAlchemy mixin to add an `updated_at` datetime field to a table that’s set to `NOW()` every time the row is updated.
-    Note that on Postgres this creates the column but doesn't update it.
+    Note that on Postgres this creates the column but update it only from Python. If you need database-level update, use
+    a trigger.
     See https://stackoverflow.com/a/71072370/735926 for a possible solution.
     """
     # NOTE: