generalize sql server check for id col to accommodate ORM cases

Fixed issues that prevented the new usage patterns for using DML with ORM
objects presented at :ref:`orm_dml_returning_objects` from working
correctly with the SQL Server pyodbc dialect.

Here we add a step to look in compile_state._dict_values more thoroughly
for the keys we need to determine "identity insert" or not, and also
add a new compiler variable dml_compile_state so that we can skip the
ORM's compile_state if present.

Fixes: #8210
Change-Id: Idbd76bb3eb075c647dc6c1cb78f7315c821e15f7

2 files changed, 59 insertions, 13 deletions

diff --git a/test/orm/test_update_delete.py b/test/orm/test_update_delete.py
index 22d827be9..933d2bb1f 100644
--- a/test/orm/test_update_delete.py
+++ b/test/orm/test_update_delete.py
@@ -2253,21 +2253,45 @@ class LoadFromReturningTest(fixtures.MappedTest):
                 [User(name="jack", age=52), User(name="jill", age=34)],
             )
 
-    def test_load_from_insert(self, connection):
+    @testing.combinations(
+        ("single",),
+        ("multiple", testing.requires.multivalues_inserts),
+        argnames="params",
+    )
+    def test_load_from_insert(self, connection, params):
         User = self.classes.User
 
-        stmt = (
-            insert(User)
-            .values({User.id: 5, User.age: 25, User.name: "spongebob"})
-            .returning(User)
-        )
+        if params == "multiple":
+            values = [
+                {User.id: 5, User.age: 25, User.name: "spongebob"},
+                {User.id: 6, User.age: 30, User.name: "patrick"},
+                {User.id: 7, User.age: 35, User.name: "squidward"},
+            ]
+        elif params == "single":
+            values = {User.id: 5, User.age: 25, User.name: "spongebob"}
+        else:
+            assert False
+
+        stmt = insert(User).values(values).returning(User)
 
         stmt = select(User).from_statement(stmt)
 
         with Session(connection) as sess:
             rows = sess.execute(stmt).scalars().all()
 
-            eq_(
-                rows,
-                [User(name="spongebob", age=25)],
-            )
+            if params == "multiple":
+                eq_(
+                    rows,
+                    [
+                        User(name="spongebob", age=25),
+                        User(name="patrick", age=30),
+                        User(name="squidward", age=35),
+                    ],
+                )
+            elif params == "single":
+                eq_(
+                    rows,
+                    [User(name="spongebob", age=25)],
+                )
+            else:
+                assert False
diff --git a/test/sql/test_insert_exec.py b/test/sql/test_insert_exec.py
index 3e51e9450..b6945813e 100644
--- a/test/sql/test_insert_exec.py
+++ b/test/sql/test_insert_exec.py
@@ -19,6 +19,14 @@ from sqlalchemy.testing.schema import Column
 from sqlalchemy.testing.schema import Table
 
 
+class ExpectExpr:
+    def __init__(self, element):
+        self.element = element
+
+    def __clause_element__(self):
+        return self.element
+
+
 class InsertExecTest(fixtures.TablesTest):
     __backend__ = True
 
@@ -35,13 +43,27 @@ class InsertExecTest(fixtures.TablesTest):
         )
 
     @testing.requires.multivalues_inserts
-    def test_multivalues_insert(self, connection):
+    @testing.combinations("string", "column", "expect", argnames="keytype")
+    def test_multivalues_insert(self, connection, keytype):
+
         users = self.tables.users
+
+        if keytype == "string":
+            user_id, user_name = "user_id", "user_name"
+        elif keytype == "column":
+            user_id, user_name = users.c.user_id, users.c.user_name
+        elif keytype == "expect":
+            user_id, user_name = ExpectExpr(users.c.user_id), ExpectExpr(
+                users.c.user_name
+            )
+        else:
+            assert False
+
         connection.execute(
             users.insert().values(
                 [
-                    {"user_id": 7, "user_name": "jack"},
-                    {"user_id": 8, "user_name": "ed"},
+                    {user_id: 7, user_name: "jack"},
+                    {user_id: 8, user_name: "ed"},
                 ]
             )
         )