斯卡拉對象

-1

內的對象的序列環，我有以下案例類斯卡拉對象

case class BusinessInput(userId: String, name: String, location: Point, address: Option[String], phonenumber: Option[String], email: Option[String], hours: Seq[BusinessHoursInput])

而下面BusinessHours案例類：

case class BusinessHoursInput(weekDay: Int, startTime: Time, endTime: Time)

我使用光滑，我試圖加BusinessInput的BusinessHours行添加到BusinessInput的小時字段中的每個BusinessHoursinput對象的數據庫。我曾嘗試以下：

_ <- for(businessHours <- businessInput.hours) BusinessHours += BusinessHoursRow(businessRow.businessId, businessHours.weekDay, businessHours.startTime, businessHours.endTime)

但我被困在下面的錯誤：

value map is not a member of Unit 
[error]  _ <- for(businessHours <- businessInput.hours) BusinessHours += BusinessHoursRow(businessRow.businessId, businessHours.weekDay, businessHours.startTime, businessHours.endTime) 
[error]       ^

編輯：

這裏是我的回購的創造功能，在那裏我第一次嘗試插入一個BusinessRow對象，然後從該插入中獲取自動增量的Id，並使用先前插入的業務對象的Business Id插入businessHours對象的列表。然後我想返回業務對象，我第一次插入：

def create(businessInput: BusinessInput): Future[BusinessRow] = db.run(for { 
    // We create a projection of just the Business Columns, since we're not inserting a value for the id column 
    businessRow <- (Business.map(b => (b.userId, b.name, b.location, b.address, b.phonenumber, b.email)) 
    // Now define it to return the id, because we want to know what id was generated for the Business 
    returning Business.map(_.businessId) 
    // And we define a transformation for the returned value, which combines our original parameters with the 
    // returned id 
    into((userIdAndBusiness, id) => BusinessRow(id, userIdAndBusiness._1, userIdAndBusiness._2, userIdAndBusiness._3, userIdAndBusiness._4, userIdAndBusiness._5, userIdAndBusiness._6)) 
    // And finally, insert the business into the database 
) +=(businessInput.userId, businessInput.name, businessInput.location, businessInput.address, businessInput.phonenumber, businessInput.email) 
// Insert a sequence of BusinessHours objects 
    _ = for(businessHours <- businessInput.hours) BusinessHours += BusinessHoursRow(businessRow.businessId, businessHours.weekDay, businessHours.startTime, businessHours.endTime) 

    } yield (businessRow) 
)

這裏是打印出來的是什麼時間場的樣子：

hours -> Vector(ListMap(weekDay -> 1, startTime -> 07:00, endTime -> 10:00), ListMap(weekDay -> 2, startTime -> 07:00, endTime -> 10:00))

，現在我收到以下錯誤：

scala.collection.immutable.ListMap$Node cannot be cast to dao.BusinessHoursInput

來源

2017-08-25 john

我很困惑_ <-'，你想做什麼？ – DanGordon

請首先看看[Scala collections doc]（https://docs.scala-lang.org/overviews/collections/overview.html），以及Scala哲學如何關於不變性（而不是像'+ = '）。 – cchantep

如果此行是對收益的理解裏面，你需要第一<-更改爲=。因爲BusinessHours += ...返回Unit，而_ <-被拆成flatMap或map。您也可以將BusinessHours += ...放入yield。

來源

2017-08-25 15:00:27

問題是，您正在使用的理解翻譯爲map。並且地圖需要將hours: Seq[BusinessHoursInput]轉換爲其他內容。在地圖裏面你這樣做：BusinessHours += BusinessHoursRow(businessRow.businessId, businessHours.weekDay, businessHours.startTime, businessHours.endTime) 這個選項不會將hours轉換成別的東西。它將BusinessHoursRow添加到BusinessHours並且該操作返回單位。

那麼如何解決呢？

1）BusinessHours變換BusinessHoursInput到BusinessHoursRow，然後將其插入：

var businessHoursRows = businessInput.hours.map { businessHoursInput => 
    BusinessHoursRow(businessHoursInput.businessId, businessHoursInput.weekDay, 
    businessHoursInput.startTime, businessHoursInput.endTime) 
} 
BusinessHours ++= businessHoursRows

2）使用的foreach代替map：你如何與`啓動代碼

businessInput.hours.foreach { businessHoursInput => 
    businessHoursRows += BusinessHoursRow(businessHoursInput.businessId, businessHoursInput.weekDay, 
    businessHoursInput.startTime, businessHoursInput.endTime) 
}

來源

2017-08-25 15:19:56

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