如何为Sqlalchemy编写原始SQL查询

Question

我有这个原始的SQL查询：

select tablename.id, tablename.prodId, tablename.status
from tablename inner join (
  select max(tablename.id) id, tablename.prodid
  from tablename t
  where not exists (
    select 1 from tablename
    where prodid = t.prodid and status in ('Success', 'Fail')
  ) 
  group by tablename.prodid
) g on g.id = t.id

如何用Sqlalchemy Core（不是ORM）语法编写？

我使用了Postgresql。 我对此声明有疑问：

select max(t.id) id, t.serial_id
      from ppod_register t
      where not exists (
        select 1 from ppod_register
        where serial_id = t.serial_id and register_status in ('SUCCESS', 'ERROR_DEVICE')
      )

我尝试使用sqlalechemy：

_exists = sql.select([1]) \
        .select_from(ppod_register) \
        .where(ppod_register.c.register_status.in_((PpodRegisterStatus.SUCCESS, PpodRegisterStatus.ERROR_DEVICE))) \
        .where(serial_id_p == ppod_register.c.serial_id)

    from sqlalchemy import exists
    _exists = exists(_exists)
    query = sql.select([serial_id_p]).where(~_exists)

但是那当然行不通。 我该怎么做这样的声明：

where serial_id = t.serial_id and register_status in ('SUCCESS', 'ERROR_DEVICE')