include column.default, column.onupdate in eager_defaults

Fixed bug in the behavior of the :paramref:`_orm.Mapper.eager_defaults`
parameter such that client-side SQL default or onupdate expressions in the
table definition alone will trigger a fetch operation using RETURNING or
SELECT when the ORM emits an INSERT or UPDATE for the row. Previously, only
server side defaults established as part of table DDL and/or server-side
onupdate expressions would trigger this fetch, even though client-side SQL
expressions would be included when the fetch was rendered.

Fixes: #7438
Change-Id: Iba719298ba4a26d185edec97ba77d2d54585e5a4

1 files changed, 19 insertions, 3 deletions

diff --git a/lib/sqlalchemy/sql/dml.py b/lib/sqlalchemy/sql/dml.py
index 76a16eb1c..9d489ed98 100644
--- a/lib/sqlalchemy/sql/dml.py
+++ b/lib/sqlalchemy/sql/dml.py
@@ -989,10 +989,26 @@ class ValuesBase(UpdateBase):
             :attr:`_engine.CursorResult.inserted_primary_key_rows`
 
         """
+
+        if self._return_defaults:
+            # note _return_defaults_columns = () means return all columns,
+            # so if we have been here before, only update collection if there
+            # are columns in the collection
+            if self._return_defaults_columns and cols:
+                self._return_defaults_columns = tuple(
+                    set(self._return_defaults_columns).union(
+                        coercions.expect(roles.ColumnsClauseRole, c)
+                        for c in cols
+                    )
+                )
+            else:
+                # set for all columns
+                self._return_defaults_columns = ()
+        else:
+            self._return_defaults_columns = tuple(
+                coercions.expect(roles.ColumnsClauseRole, c) for c in cols
+            )
         self._return_defaults = True
-        self._return_defaults_columns = tuple(
-            coercions.expect(roles.ColumnsClauseRole, c) for c in cols
-        )
         return self