ANORM查詢，壓平沒有找到

Question

在矢部例子，有此查詢：

def allWithAuthor:List[(Post,User)] = 
      SQL(
       """ 
        select * from Post p 
        join User u on p.author_id = u.id 
        order by p.postedAt desc 
       """ 
      ).as(Post ~< User ^^ flatten *) 

在我的應用程序，我有一個非常類似的查詢：

def findAll:List[(Album,Artist)] = 
     SQL(
     """ 
      select * from Album al 
      join Artist ar on al.artist_id = ar.id 
      order by al.nbVotes desc 
      limit 100 
     """ 
    ).as(Album ~< Artist ^^ flatten *) 

我有這樣的編譯錯誤：

The file /app/models.scala could not be compiled. Error raised is : not found: 
value flatten Error occurred in an application involving default arguments. 

我不覺得與矢部工作示例的區別...

你爲什麼我有這個錯誤？

Answer 1

至於建議中的意見，增加

import play.db.anorm.SqlParser._