[Sqlalchemy-tickets] Issue #3556: update executemany() enhancement breaks versioning (zzzeek/sqlalchemy)

[Mike B. <iss...@bi...>]

New issue 3556: update executemany() enhancement breaks versioning
https://bitbucket.org/zzzeek/sqlalchemy/issues/3556/update-executemany-enhancement-breaks

Mike Bayer:


```
#!diff

diff --git a/test/orm/test_versioning.py b/test/orm/test_versioning.py
index d46799c..67d580e 100644
--- a/test/orm/test_versioning.py
+++ b/test/orm/test_versioning.py
@@ -952,6 +952,46 @@ class ServerVersioningTest(fixtures.MappedTest):
             )
         self.assert_sql_execution(testing.db, sess.flush, *statements)
 
+    def test_multi_update(self):
+        sess = self._fixture()
+
+        f1 = self.classes.Foo(value='f1')
+        f2 = self.classes.Foo(value='f2')
+        f3 = self.classes.Foo(value='f3')
+        sess.add_all([f1, f2, f3])
+        sess.flush()
+
+        f1.value = 'f1a'
+        f2.value = 'f2a'
+        f3.value = 'f3a'
+
+        statements = [
+            # note that the assertsql tests the rule against
+            # "default" - on a "returning" backend, the statement
+            # includes "RETURNING"
+            CompiledSQL(
+                "UPDATE version_table SET version_id=2, value=:value "
+                "WHERE version_table.id = :version_table_id AND "
+                "version_table.version_id = :version_table_version_id",
+                lambda ctx: [
+                    {
+                        "version_table_id": 1,
+                        "version_table_version_id": 1, "value": "f2"}]
+            )
+        ]
+        if not testing.db.dialect.implicit_returning:
+            # DBs without implicit returning, we must immediately
+            # SELECT for the new version id
+            statements.append(
+                CompiledSQL(
+                    "SELECT version_table.version_id "
+                    "AS version_table_version_id "
+                    "FROM version_table WHERE version_table.id = :param_1",
+                    lambda ctx: [{"param_1": 1}]
+                )
+            )
+        self.assert_sql_execution(testing.db, sess.flush, *statements)
+
     def test_delete_col(self):
         sess = self._fixture()
 

```

PG:

```
#!


File "/Users/classic/dev/sqlalchemy/test/../lib/sqlalchemy/engine/result.py", line 1026, in fetchone
    self.cursor, self.context)
  File "/Users/classic/dev/sqlalchemy/test/../lib/sqlalchemy/engine/base.py", line 1341, in _handle_dbapi_exception
    exc_info
  File "/Users/classic/dev/sqlalchemy/test/../lib/sqlalchemy/util/compat.py", line 199, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb)
  File "/Users/classic/dev/sqlalchemy/test/../lib/sqlalchemy/engine/result.py", line 1017, in fetchone
    row = self._fetchone_impl()
  File "/Users/classic/dev/sqlalchemy/test/../lib/sqlalchemy/engine/result.py", line 898, in _fetchone_impl
    return self.cursor.fetchone()
ProgrammingError: (psycopg2.ProgrammingError) no results to fetch

```