Support Column objects in the SET clause for upsert

Established support for :class:`_schema.Column` objects as well as ORM
instrumented attributes as keys in the ``set_`` dictionary passed to the
:meth:`_postgresql.Insert.on_conflict_do_update` and
:meth:`_sqlite.Insert.on_conflict_do_update` methods, which match to the
:class:`_schema.Column` objects in the ``.c`` collection of the target
:class:`_schema.Table`. Previously,  only string column names were
expected; a column expression would be assumed to be an out-of-table
expression that would render fully along with a warning.

Fixes: #5722
Change-Id: Ice73b501d721c28d978a0277a83cedc6aff756a9

1 files changed, 19 insertions, 13 deletions

diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index 3c33d9ee8..3a458ebed 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -2147,22 +2147,28 @@ class PGCompiler(compiler.SQLCompiler):
         cols = insert_statement.table.c
         for c in cols:
             col_key = c.key
+
             if col_key in set_parameters:
                 value = set_parameters.pop(col_key)
-                if coercions._is_literal(value):
-                    value = elements.BindParameter(None, value, type_=c.type)
+            elif c in set_parameters:
+                value = set_parameters.pop(c)
+            else:
+                continue
 
-                else:
-                    if (
-                        isinstance(value, elements.BindParameter)
-                        and value.type._isnull
-                    ):
-                        value = value._clone()
-                        value.type = c.type
-                value_text = self.process(value.self_group(), use_schema=False)
-
-                key_text = self.preparer.quote(col_key)
-                action_set_ops.append("%s = %s" % (key_text, value_text))
+            if coercions._is_literal(value):
+                value = elements.BindParameter(None, value, type_=c.type)
+
+            else:
+                if (
+                    isinstance(value, elements.BindParameter)
+                    and value.type._isnull
+                ):
+                    value = value._clone()
+                    value.type = c.type
+            value_text = self.process(value.self_group(), use_schema=False)
+
+            key_text = self.preparer.quote(col_key)
+            action_set_ops.append("%s = %s" % (key_text, value_text))
 
         # check for names that don't match columns
         if set_parameters: