diff --git a/graphene/contrib/sqlalchemy/types.py b/graphene/contrib/sqlalchemy/types.py
index f466a1af..20202ab7 100644
--- a/graphene/contrib/sqlalchemy/types.py
+++ b/graphene/contrib/sqlalchemy/types.py
@@ -33,16 +33,16 @@ class SQLAlchemyObjectTypeMeta(ObjectTypeMeta):
             converted_relationship = convert_sqlalchemy_relationship(relationship)
             cls.add_to_class(relationship.key, converted_relationship)
 
-        for column in inspected_model.columns:
-            is_not_in_only = only_fields and column.name not in only_fields
-            is_already_created = column.name in already_created_fields
-            is_excluded = column.name in exclude_fields or is_already_created
+        for name, column in inspected_model.columns.items():
+            is_not_in_only = only_fields and name not in only_fields
+            is_already_created = name in already_created_fields
+            is_excluded = name in exclude_fields or is_already_created
             if is_not_in_only or is_excluded:
                 # We skip this field if we specify only_fields and is not
                 # in there. Or when we excldue this field in exclude_fields
                 continue
             converted_column = convert_sqlalchemy_column(column)
-            cls.add_to_class(column.name, converted_column)
+            cls.add_to_class(name, converted_column)
 
     def construct(cls, *args, **kwargs):
         cls = super(SQLAlchemyObjectTypeMeta, cls).construct(*args, **kwargs)