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, 9 insertions, 1 deletions

diff --git a/lib/sqlalchemy/sql/dml.py b/lib/sqlalchemy/sql/dml.py
index 2ed3be9cb..e99f35418 100644
--- a/lib/sqlalchemy/sql/dml.py
+++ b/lib/sqlalchemy/sql/dml.py
@@ -263,7 +263,7 @@ class DMLState(CompileState):
 
     def _process_select_values(self, statement: ValuesBase) -> None:
         assert statement._select_names is not None
-        parameters = {
+        parameters: MutableMapping[_DMLColumnElement, Any] = {
             coercions.expect(roles.DMLColumnRole, name, as_key=True): Null()
             for name in statement._select_names
         }
@@ -312,6 +312,14 @@ class InsertDMLState(DMLState):
         if statement._multi_values:
             self._process_multi_values(statement)
 
+    @util.memoized_property
+    def _insert_col_keys(self) -> List[str]:
+        # this is also done in crud.py -> _key_getters_for_crud_column
+        return [
+            coercions.expect_as_key(roles.DMLColumnRole, col)
+            for col in self._dict_parameters or ()
+        ]
+
 
 @CompileState.plugin_for("default", "update")
 class UpdateDMLState(DMLState):