元组的元素太多：27，允许：22答案

【问题标题】：Too many elements for Tuple: 27, allowed: 22元组的元素太多：27，允许：22
【发布时间】：2016-09-08 22:46:50
【问题描述】：

我是 Slick 的新手并使用 Slick 3.1.1。我的桌子看起来像

import java.sql.{Blob, Timestamp}

import slick.collection.heterogeneous.HNil

import slick.driver.MySQLDriver.api._


case class AnomalyC(id: Int, serviceName: String, serviceId: String, timeUpdated: Timestamp, timestamp: Timestamp, anomalyCategoryId: Int,
                    userGroup:Int, riskValue: Float, activityTypeId: Int, destinationHost: String, userName: String, tenantId: Int, information:Blob, timeCreated: Timestamp, userId: Int, anomalyType:Int, anomalyValue:String, measure:Int,
                    userAction:Int, uniqueIdentifier:Int, similarCount:Int, trainingValue:String, state: Int, riskLevel:Int, userRiskLevel:Int,
                    userRiskScore: Float, response:Int)
class Anomaly(tag:Tag) extends Table[AnomalyC](tag, "Anomaly") {
  def id = column[Int]("id")
  def serviceName = column[String]("ServiceName")
  def serviceId = column[Int]("ServiceId")
  def timeUpdated = column[Timestamp]("TimeUpdated")
  def timestamp = column[Timestamp]("Timestamp")
  def anomalyCategoryId = column[Int]("AnomalyCategoryId")
  def userGroup = column[Int]("UserGroup")
  def riskValue = column[Float]("RiskValue")
  def activityTypeId = column[Int]("ActivityTypeId")
  def destinationHost = column[String]("DestinationHost")
  def userName = column[String]("UserName")
  def tenantId = column[Int]("TenantId")
  def information = column[Blob]("Information")
  def timeCreated = column[Timestamp]("TimeCreated")
  def userId = column[Int]("UserId")
  def anomalyType = column[Int]("AnomalyType")
  def anomalyValue = column[String]("AnomalyValue")
  def measure = column[Int]("Measure")
  def userAction = column[Int]("UserAction")
  def uniqueIdentifier = column[String]("UniqueIdentifier")
  def similarCount = column[Int]("SimilarCount")
  def trainingValue = column[String]("TrainingValue")
  def state = column[Int]("State")
  def riskLevel = column[Int]("RiskLevel")
  def userRiskLevel = column[Int]("UserRiskLevel")
  def userRiskScore = column[Float]("UserRiskScore")
  def response = column[Int]("Response")

  def * = (id, serviceName, serviceId, timeUpdated, timestamp, anomalyCategoryId, userGroup,
    riskValue, activityTypeId, destinationHost, userName, tenantId, information, timeCreated, userId, anomalyType, anomalyValue,
    measure, userAction, uniqueIdentifier, similarCount, trainingValue, state, riskLevel, userRiskLevel, userRiskScore, response)

}

当我运行这个时，我得到错误

Error:(57, 11) too many elements for tuple: 27, allowed: 22
  def * = (id, serviceName, serviceId, timeUpdated, timestamp, anomalyCategoryId, userGroup,
          ^

我该怎么办？

【问题讨论】：

正如建议的那样，HLists 是目前的发展方向。 Here's an example，包括您如何自定义 Slick 的代码生成功能以自动为您定义大表。

标签： scala slick slick-3.0

【解决方案1】：

您可以使用 HList。 Slick 有它自己的实现，或者为了更好的互操作性，您可以使用 Shapeless。这是一篇解释它的文章：http://underscore.io/blog/posts/2015/08/08/slickless.html

或者，您可以使用案例类而不是元组。

【讨论】：

哪个无形？我用的是Maven，你用的是哪个？ mvnrepository.com/search?q=shapeless
这个：github.com/milessabin/shapeless。看起来这是最新的 com.chuusai:shapeless:2.3.1
实际上嵌套元组是另一种选择！

【解决方案2】：

根据@cvogt 提供的方向，以下内容对我有用。

import java.sql.{Blob, Timestamp}

import slick.collection.heterogeneous.HNil
import slick.collection.heterogeneous.syntax._
import slick.driver.MySQLDriver.api._

class Anomaly(tag:Tag) extends Table[Int :: String :: Int :: Timestamp :: Timestamp :: Int :: Int :: Float :: Int :: String
   :: String :: Int ::Blob :: Timestamp :: Int ::Int ::String ::Int ::Int ::String ::Int ::String :: Int ::Int ::Int ::
  Float :: Int :: HNil ](tag, "Anomaly") {

  def id = column[Int]("id")
  def serviceName = column[String]("ServiceName")
  def serviceId = column[Int]("ServiceId")
  def timeUpdated = column[Timestamp]("TimeUpdated")
  def timestamp = column[Timestamp]("Timestamp")
  def anomalyCategoryId = column[Int]("AnomalyCategoryId")
  def userGroup = column[Int]("UserGroup")
  def riskValue = column[Float]("RiskValue")
  def activityTypeId = column[Int]("ActivityTypeId")
  def destinationHost = column[String]("DestinationHost")
  def userName = column[String]("UserName")
  def tenantId = column[Int]("TenantId")
  def information = column[Blob]("Information")
  def timeCreated = column[Timestamp]("TimeCreated")
  def userId = column[Int]("UserId")
  def anomalyType = column[Int]("AnomalyType")
  def anomalyValue = column[String]("AnomalyValue")
  def measure = column[Int]("Measure")
  def userAction = column[Int]("UserAction")
  def uniqueIdentifier = column[String]("UniqueIdentifier")
  def similarCount = column[Int]("SimilarCount")
  def trainingValue = column[String]("TrainingValue")
  def state = column[Int]("State")
  def riskLevel = column[Int]("RiskLevel")
  def userRiskLevel = column[Int]("UserRiskLevel")
  def userRiskScore = column[Float]("UserRiskScore")
  def response = column[Int]("Response")

   def *  = id :: serviceName :: serviceId :: timeUpdated :: timestamp :: anomalyCategoryId :: userGroup ::
  riskValue :: activityTypeId :: destinationHost :: userName :: tenantId :: information :: timeCreated :: userId :: anomalyType :: anomalyValue ::
  measure :: userAction :: uniqueIdentifier :: similarCount :: trainingValue :: state :: riskLevel :: userRiskLevel :: userRiskScore :: response :: HNil
}

构建运行并测试通过，但是，我仍然看到 IntelliJ 抱怨以下错误

【讨论】：

【解决方案3】：

根据@insan-e 的回答，我重新编写了这个，这也有效。我更喜欢这种方法，但是我不完全理解代码

import java.sql.{Blob, Timestamp}

import slick.driver.MySQLDriver.api._

case class Anomaly1(id:Int, serviceName:String, serviceId: Int, timeUpdated: Timestamp, timeStamp: Timestamp,
                    anomalyCategoryId: Int, userGroup: Int, riskValue: Float, activityTypeId: Int, destinationHost: String, userName: String)

case class Anomaly2(tenantId: Int, information:Blob, timeCreated: Timestamp, userId: Int, anomalyType:Int, anomalyValue: String, measure: Int, userAction: Int,
                   uniqueIdentifier: String, similarCount: Int, trainingValue: String, state: Int, riskLevel: Int,
                    userRiskLevel: Int, userRiskScore: Float, response: Int)

case class AnomalyRow(anomaly1: Anomaly1, anomaly2: Anomaly2)

class Anomaly(tag:Tag) extends Table[AnomalyRow](tag, "Anomaly") {

  def id = column[Int]("id")
  def serviceName = column[String]("ServiceName")
  def serviceId = column[Int]("ServiceId")
  def timeUpdated = column[Timestamp]("TimeUpdated")
  def timestamp = column[Timestamp]("Timestamp")
  def anomalyCategoryId = column[Int]("AnomalyCategoryId")
  def userGroup = column[Int]("UserGroup")
  def riskValue = column[Float]("RiskValue")
  def activityTypeId = column[Int]("ActivityTypeId")
  def destinationHost = column[String]("DestinationHost")
  def userName = column[String]("UserName")
  def tenantId = column[Int]("TenantId")
  def information = column[Blob]("Information")
  def timeCreated = column[Timestamp]("TimeCreated")
  def userId = column[Int]("UserId")
  def anomalyType = column[Int]("AnomalyType")
  def anomalyValue = column[String]("AnomalyValue")
  def measure = column[Int]("Measure")
  def userAction = column[Int]("UserAction")
  def uniqueIdentifier = column[String]("UniqueIdentifier")
  def similarCount = column[Int]("SimilarCount")
  def trainingValue = column[String]("TrainingValue")
  def state = column[Int]("State")
  def riskLevel = column[Int]("RiskLevel")
  def userRiskLevel = column[Int]("UserRiskLevel")
  def userRiskScore = column[Float]("UserRiskScore")
  def response = column[Int]("Response")

  private type Anomaly1TupleType = (Int, String, Int, Timestamp, Timestamp, Int, Int, Float, Int, String, String)
  private type Anomaly2TupleType = (Int, Blob, Timestamp, Int, Int, String, Int, Int, String, Int, String, Int, Int, Int, Float, Int)
  private type AnomalyRowTupleType = (Anomaly1TupleType, Anomaly2TupleType)

  private val anomalyShapedValue = (
    (id, serviceName, serviceId, timeUpdated, timestamp, anomalyCategoryId, userGroup, riskValue, activityTypeId, destinationHost, userName),
    (tenantId, information, timeCreated, userId, anomalyType, anomalyValue, measure, userAction, uniqueIdentifier, similarCount, trainingValue, state, riskLevel, userRiskLevel, userRiskScore, response)
    ).shaped[AnomalyRowTupleType]

  private val toAnomalyRow: (AnomalyRowTupleType => AnomalyRow) = { anomalyTuple =>
    AnomalyRow(anomaly1 = Anomaly1.tupled.apply(anomalyTuple._1), anomaly2 = Anomaly2.tupled.apply(anomalyTuple._2))
  }

  private val toAnomalyTuple: (AnomalyRow => Option[AnomalyRowTupleType]) = { anomalyRow =>
    Some(Anomaly1.unapply(anomalyRow.anomaly1).get, Anomaly2.unapply(anomalyRow.anomaly2).get)
  }

  def * = anomalyShapedValue <> (toAnomalyRow, toAnomalyTuple)
}

【讨论】：

很好 .. 但如果您的任何字段的类型为 BigDecimal，则无法正常工作

【解决方案4】：

正如 cvogt 已经说过的，您可以使用嵌套案例类，它们更容易使用，请参阅 here。我知道 HLists 很强大，但恕我直言，人们强迫他们太多了......案例类有什么问题？ xD

您应该从包含 AnomalyC 类。

【讨论】：

【解决方案5】：

由于 slick 不允许超过 22 列，并抱怨找不到 tupled 和 unapply 方法。最简单的解决方案是尽可能使用嵌套案例类。示例：

https://github.com/timgent/spray-slick-template/blob/master/src/main/scala/com/timmeh/openhr/openholidays/model/LargeTableExample1.scala

【讨论】：

【解决方案6】：

使用 HList 方法，我们只需更改默认投影*。

来自文档https://scala-slick.org/doc/3.3.3/cookbook.html

【讨论】：