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
(cherry picked from commit 5806428800d2f1ac775156f90497a2fc3a644f35)

1 files changed, 18 insertions, 0 deletions

diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index 477c199c1..667dd7d3d 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -402,6 +402,18 @@ class Compiled(object):
 
     """
 
+    dml_compile_state = None
+    """Optional :class:`.CompileState` assigned at the same point that
+    .isinsert, .isupdate, or .isdelete is assigned.
+
+    This will normally be the same object as .compile_state, with the
+    exception of cases like the :class:`.ORMFromStatementCompileState`
+    object.
+
+    .. versionadded:: 1.4.40
+
+    """
+
     cache_key = None
     _gen_time = None
 
@@ -3838,6 +3850,8 @@ class SQLCompiler(Compiled):
 
         if toplevel:
             self.isinsert = True
+            if not self.dml_compile_state:
+                self.dml_compile_state = compile_state
             if not self.compile_state:
                 self.compile_state = compile_state
 
@@ -4008,6 +4022,8 @@ class SQLCompiler(Compiled):
         toplevel = not self.stack
         if toplevel:
             self.isupdate = True
+            if not self.dml_compile_state:
+                self.dml_compile_state = compile_state
             if not self.compile_state:
                 self.compile_state = compile_state
 
@@ -4134,6 +4150,8 @@ class SQLCompiler(Compiled):
         toplevel = not self.stack
         if toplevel:
             self.isdelete = True
+            if not self.dml_compile_state:
+                self.dml_compile_state = compile_state
             if not self.compile_state:
                 self.compile_state = compile_state