8
class Employee
id
name
class Location
id
city
class Work
id
employee_id
location_id
藤堂に参加:SQLAlchemyの左のカウント
select location.id, count(work.id) as count
from location
left join work
on location.id = work.location_id
group by location.id
SQLAlchemyの:
db_session.query(Location, func.count.work_id).label('count')). \
filter(location.id == work.location_id). \
group_by(location._id). \
左(ゼロを含む)のカウントで
望ましい結果
location.city count
NYC 10
SFO 5
CHI 0
生のクエリに参加
left joinを実行しているときにselectの列を指定する正しい方法は何ですか?