SQLAlchemy子查询 - 总和的平均值

Question

有没有办法在SQLAlchemy ORM中编写以下SQL语句:

SELECT AVG(a1) FROM (SELECT sum(irterm.n) AS a1 FROM irterm GROUP BY irterm.item_id);

谢谢

Answer 1

sums = session.query(func.sum(Irterm.n).label('a1')).group_by(Irterm.item_id).subquery()
average = session.query(func.avg(sums.c.a1)).scalar()