我一直在將一些MySQL查詢遷移到PostgreSQL以使用Heroku。我的大多數(shù)查詢工作正常，但當(dāng)我使用group by時，我仍然遇到類似的重復(fù)錯誤：錯誤：列“XYZ”必須出現(xiàn)在GROUP BY子句中或用于聚合函數(shù)有人能告訴我我做錯了什么嗎？MySQL 100％工作：SELECT `availables`.*FROM `availables`INNER JOIN `rooms` ON `rooms`.id = `availables`.room_idWHERE (rooms.hotel_id = 5056 AND availables.bookdate BETWEEN '2009-11-22' AND '2009-11-24')GROUP BY availables.bookdateORDER BY availables.updated_atPostgreSQL錯誤：ActiveRecord :: StatementInvalid：PGError：錯誤：列“availables.id”必須出現(xiàn)在GROUP BY子句中或用于聚合函數(shù)：SELECT“availables”。* FROM“availables”INNER JOIN“rooms”O(jiān)N“rooms”。 id =“availables”.room_id WHERE（rooms.hotel_id = 5056 AND availables.bookdate BETWEEN E'2009-10-21'EN'E'2009-10-23'）GROUP BY availables.bookdate ORDER BY availables.updated_at生成SQL的Ruby代碼：expiration = Available.find(:all,    :joins => [ :room ],    :conditions => [ "rooms.hotel_id = ? AND availables.bookdate BETWEEN ? AND ?", hostel_id, date.to_s, (date+days-1).to_s ],    :group => 'availables.bookdate',    :order => 'availables.updated_at')  預(yù)期輸出（來自MySQL查詢）：+ ----- + ------- ------- + ------------ + + --------- + ---- ----------- + --------------- +| id | 價格| 斑點| bookdate | room_id | created_at | updated_at |+ ----- + ------- ------- + ------------ + + --------- + ---- ----------- + --------------- +| 414 | 38.0 | 1 | 2009-11-22 | 1762年| 2009-11-20 ...... | 2009-11-20 ...... || 415 | 38.0 | 1 | 2009-11-23 | 1762年| 2009-11-20 ...... | 2009-11-20 ...... || 416 | 38.0 | 2 | 2009-11-24 | 1762年| 2009-11-20 ...... | 2009-11-20 ...... |+ ----- + ------- ------- + ------------ + + --------- + ---- ----------- + --------------- +集合3行