doctrine2中的子查询select * from（select ....）

Question

我想在doctrine2中查询以下内容。

SELECT  tmp.*  FROM (
SELECT
  a0_.radacctid AS radacctid0,
  a0_.nasidentifier AS user_id1
FROM
  a_radacct a0_
WHERE (
    a0_.acctstarttime_local BETWEEN '2018-09-01'
    AND '2018-09-31'
  )
LIMIT 50) AS tmp join site s on tmp.nasidentifier=s.site_token