sqlalchemy.exc.OperationalError
OperationalError: (_mysql_exceptions.OperationalError) (1055, "Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'link.rack.uuid' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by")
解决方法：
mysql.cnf
[mysqld]
sql_mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION