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

1 files changed, 16 insertions, 3 deletions

diff --git a/lib/sqlalchemy/sql/coercions.py b/lib/sqlalchemy/sql/coercions.py
index d56035db7..0b250a28e 100644
--- a/lib/sqlalchemy/sql/coercions.py
+++ b/lib/sqlalchemy/sql/coercions.py
@@ -164,6 +164,17 @@ def expect(
 
 @overload
 def expect(
+    role: Type[roles.DMLColumnRole],
+    element: Any,
+    *,
+    as_key: Literal[True] = ...,
+    **kw: Any,
+) -> str:
+    ...
+
+
+@overload
+def expect(
     role: Type[roles.LiteralValueRole],
     element: Any,
     **kw: Any,
@@ -420,9 +431,11 @@ def expect(
         )
 
 
-def expect_as_key(role, element, **kw):
-    kw["as_key"] = True
-    return expect(role, element, **kw)
+def expect_as_key(
+    role: Type[roles.DMLColumnRole], element: Any, **kw: Any
+) -> str:
+    kw.pop("as_key", None)
+    return expect(role, element, as_key=True, **kw)
 
 
 def expect_col_expression_collection(