It looks like it's not actualy replacing values when using a Query object and it's methods. Getting this for first() and get()
experts_mapper = mapper(Expert, experts) currencies_mapper = mapper(Currency, currencies) inputs_mapper = mapper(Input, inputs, properties={'expert' : relation(Expert, backref="expert")} ) inputf = session.query(Input).first() print(inputf.expert) ----------------------------------------------------------------------- sqlalchemy.exc.ProgrammingError: (ProgrammingError) (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '%s, %s' at line 3") b'SELECT inputs.input_id AS inputs_input_id, inputs.expert_id AS inputs_expert_id, inputs.input_name AS inputs_input_name, inputs.input_default AS inputs_input_default, inputs.input_start AS inputs_input_start, inputs.input_step AS inputs_input_step, inputs.input_end AS inputs_input_end, inputs.input_optimize AS inputs_input_optimize \nFROM inputs \n LIMIT %s, %s' (0, 1) File "C:\Users\Bogdan\Desktop\forex\metatester\tester.py", line 33, in <module> inputf = session.query(Input).first() File "C:\Users\Bogdan\AppData\Roaming\Python\Python32\site-packages \sqlalchemy\orm\query.py", line 1719, in first ret = list(self[0:1]) File "C:\Users\Bogdan\AppData\Roaming\Python\Python32\site-packages \sqlalchemy\orm\query.py", line 1616, in __getitem__ return list(res) File "C:\Users\Bogdan\AppData\Roaming\Python\Python32\site-packages \sqlalchemy\orm\query.py", line 1788, in __iter__ return self._execute_and_instances(context) File "C:\Users\Bogdan\AppData\Roaming\Python\Python32\site-packages \sqlalchemy\orm\query.py", line 1803, in _execute_and_instances result = conn.execute(querycontext.statement, self._params) File "C:\Users\Bogdan\AppData\Roaming\Python\Python32\site-packages \sqlalchemy\engine\base.py", line 1358, in execute params) File "C:\Users\Bogdan\AppData\Roaming\Python\Python32\site-packages \sqlalchemy\engine\base.py", line 1491, in _execute_clauseelement compiled_sql, distilled_params File "C:\Users\Bogdan\AppData\Roaming\Python\Python32\site-packages \sqlalchemy\engine\base.py", line 1599, in _execute_context context) File "C:\Users\Bogdan\AppData\Roaming\Python\Python32\site-packages \sqlalchemy\engine\base.py", line 1736, in _handle_dbapi_exception from e -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.