Question

我有以下案例类

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

以下BusinessHours案例类：

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

我正在使用Slick，我正在尝试将BusinessHours行添加到BusinessInput的hours字段中的每个BusinessHoursinput对象的DB中。我尝试过以下方法：

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

但是我坚持以下错误：

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

编辑：

这是我的Repo的创建功能，我首先尝试插入BusinessRow对象，然后从该插入中获取自动增量的Id，并使用先前插入的业务对象中的Business Id插入businessHours对象列表。然后我想返回我第一次插入的业务对象：

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)
  )

以下是打印小时字段的内容：

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

现在我收到以下错误：

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

Answer 1

如果此行在for-yield理解中，则需要将第一个<-更改为=。由于BusinessHours += ...会返回Unit，_ <-会被flatMap或map删除。

或者，您可以将BusinessHours += ...放入yield。

Answer 2

问题是你正在使用被翻译成map的理解。地图需要将hours: Seq[BusinessHoursInput]转换为其他内容。在地图内你这样做：BusinessHours += BusinessHoursRow(businessRow.businessId, businessHours.weekDay, businessHours.startTime, businessHours.endTime) 此选项不会将hours转换为其他内容。它在BusinessHoursRow中添加BusinessHours，该操作返回Unit。

那么如何解决呢？

1）将BusinessHoursInput转换为BusinessHoursRow，然后将其插入BusinessHours：

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

2）使用foreach代替map：

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

Scala for对象内对象的Seq循环

2 个答案: