- Fixed a major regression in the 1.0 series where the version_id_counter

feature would cause an object's version counter to be incremented
when there was no net change to the object's row, but instead an object
related to it via relationship (e.g. typically many-to-one)
were associated or de-associated with it, resulting in an UPDATE
statement that updates the object's version counter and nothing else.
In the use case where the relatively recent "server side" and/or
"programmatic/conditional" version counter feature were used
(e.g. setting version_id_generator to False), the bug could cause an
UPDATE without a valid SET clause to be emitted.
fixes #3465

1 files changed, 18 insertions, 1 deletions

diff --git a/lib/sqlalchemy/orm/persistence.py b/lib/sqlalchemy/orm/persistence.py
index a42ed2f7c..4f074df8e 100644
--- a/lib/sqlalchemy/orm/persistence.py
+++ b/lib/sqlalchemy/orm/persistence.py
@@ -461,6 +461,23 @@ def _collect_update_commands(
 
         if update_version_id is not None and \
                 mapper.version_id_col in mapper._cols_by_table[table]:
+
+            if not bulk and not (params or value_params):
+                # HACK: check for history in other tables, in case the
+                # history is only in a different table than the one
+                # where the version_id_col is.  This logic was lost
+                # from 0.9 -> 1.0.0 and restored in 1.0.6.
+                for prop in mapper._columntoproperty.values():
+                    history = (
+                        state.manager[prop.key].impl.get_history(
+                            state, state_dict,
+                            attributes.PASSIVE_NO_INITIALIZE))
+                    if history.added:
+                        break
+                else:
+                    # no net change, break
+                    continue
+
             col = mapper.version_id_col
             params[col._label] = update_version_id
 
@@ -469,7 +486,7 @@ def _collect_update_commands(
                 val = mapper.version_id_generator(update_version_id)
                 params[col.key] = val
 
-        if not (params or value_params):
+        elif not (params or value_params):
             continue
 
         if bulk: