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Slickでマッピングされたプロジェクションを使用してクエリを追加する方法を見つけようとしていますが、何を試しても次のエラーに遭遇し続けます:

[error] (run-main) scala.slick.SlickException: 
    Select(TableNode, "USER_NAME") found. This is typically 
    caused by an attempt to use a "raw" table object directly 
    in a query without introducing it through a generator.
scala.slick.SlickException: Select(TableNode, "USER_NAME") 
    found. This is typically caused by an attempt to use a "raw" table 
    object directly in a query without introducing it through a generator.
    at scala.slick.ast.Select.<init>(Node.scala:340)
    at scala.slick.ast.Select.copy(Node.scala:338)
    at scala.slick.ast.Select.nodeRebuild(Node.scala:345)
    at scala.slick.ast.Select.nodeRebuild(Node.scala:338)
    at scala.slick.ast.UnaryNode$class.nodeRebuild(Node.scala:141)
    at scala.slick.ast.Select.nodeRebuild(Node.scala:338)
    at scala.slick.ast.SimpleNode$$anonfun$nodeMapChildren$1.apply(Node.scala:62)
    at scala.slick.ast.SimpleNode$$anonfun$nodeMapChildren$1.apply(Node.scala:62)
    at scala.Option.map(Option.scala:145)
    at scala.slick.ast.SimpleNode$class.nodeMapChildren(Node.scala:62)
    at scala.slick.ast.Select.nodeMapChildren(Node.scala:338)
    at scala.slick.compiler.Inline.scala$slick$compiler$Inline$$tr$1(Inline.scala:67)
    at scala.slick.compiler.Inline$$anonfun$scala$slick$compiler$Inline$$tr$1$3.apply(Inline.scala:67)
    at scala.slick.compiler.Inline$$anonfun$scala$slick$compiler$Inline$$tr$1$3.apply(Inline.scala:67)
    at scala.slick.ast.Node$$anonfun$nodeMapNodes$1.apply(Node.scala:38)
    at scala.slick.ast.Node$$anonfun$nodeMapNodes$1.apply(Node.scala:37)
    at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
    at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
    at scala.slick.ast.Node$class.nodeMapNodes(Node.scala:37)
    at scala.slick.ast.ProductNode$$anon$3.nodeMapNodes(Node.scala:82)
    at scala.slick.ast.SimpleNode$class.nodeMapChildren(Node.scala:62)
    at scala.slick.ast.ProductNode$$anon$3.nodeMapChildren(Node.scala:82)
    at scala.slick.compiler.Inline.scala$slick$compiler$Inline$$tr$1(Inline.scala:67)
    at scala.slick.compiler.Inline$$anonfun$scala$slick$compiler$Inline$$tr$1$3.apply(Inline.scala:67)
    at scala.slick.compiler.Inline$$anonfun$scala$slick$compiler$Inline$$tr$1$3.apply(Inline.scala:67)
    at scala.slick.ast.Node$$anonfun$nodeMapNodes$1.apply(Node.scala:38)
    at scala.slick.ast.Node$$anonfun$nodeMapNodes$1.apply(Node.scala:37)
    at scala.collection.immutable.List.foreach(List.scala:309)
    at scala.slick.ast.Node$class.nodeMapNodes(Node.scala:37)
    at scala.slick.ast.Pure.nodeMapNodes(Node.scala:151)
    at scala.slick.ast.SimpleNode$class.nodeMapChildren(Node.scala:62)
    at scala.slick.ast.Pure.nodeMapChildren(Node.scala:151)
    at scala.slick.compiler.Inline.scala$slick$compiler$Inline$$tr$1(Inline.scala:67)
    at scala.slick.compiler.Inline$$anonfun$scala$slick$compiler$Inline$$tr$1$3.apply(Inline.scala:67)
    at scala.slick.compiler.Inline$$anonfun$scala$slick$compiler$Inline$$tr$1$3.apply(Inline.scala:67)
    at scala.slick.ast.Node$$anonfun$nodeMapNodes$1.apply(Node.scala:38)
    at scala.slick.ast.Node$$anonfun$nodeMapNodes$1.apply(Node.scala:37)
    at scala.collection.immutable.List.foreach(List.scala:309)

私は Scala と Slick が初めてで、メッセージの意味を理解するのに苦労しています。これと関係があると思います（滑らかなドキュメントから取得）：

Slick はテーブル オブジェクトを内部で複製するため、テーブル オブジェクトに余分な状態を追加しないでください (ただし、追加のメソッドは問題ありません)。また、テーブルの実際のオブジェクトが静的な場所 (つまり、最上位または他のオブジェクト内にのみネストされた場所) で定義されていないことを確認してください。テーブルに val を (匿名の構造型または別のクラス定義で) 使用することは、どこでも問題ありません。 持ち上げられた埋め込み

slick-examples の MultiDBCakeExample を次のコードのように変更し、いくつかの順列を試しましたが、うまくいきませんでした。以下のコードは、slick-examples プロジェクトのフォーク バージョンから取得したものです。これは私の変更へのリンクです。

package com.typesafe.slick.examples.lifted

import scala.slick.driver.ExtendedProfile
import scala.slick.session.Session
import scala.slick.driver.H2Driver
import scala.slick.driver.SQLiteDriver

trait Profile {
  val profile: ExtendedProfile
}

case class Picture(url: String, id: Option[Int] = None)

trait PictureComponent { this: Profile => //requires a Profile to be mixed in...
  import profile.simple._ //...to be able import profile.simple._ 

  object Pictures extends Table[(String, Option[Int])]("PICTURES") {
    //                    ^ Table comes from the *current* profile
    def id = column[Option[Int]]("PIC_ID", O.PrimaryKey, O.AutoInc)
    def url = column[String]("PIC_URL", O.NotNull)

    def * = url ~ id

    val autoInc = url returning id into { case (url, id) => Picture(url, id) }

    def insert(picture: Picture)(implicit session: Session): Picture = {
      autoInc.insert(picture.url)
    }
  }
}

case class User(name: String, picture: Picture, id: Option[Int] = None)

case class UserAndPicId(name: String, picId: Int)

trait UserComponent { this: Profile with PictureComponent => //requires Profile and Picture (see def insert)
  import profile.simple._

  object Users extends Table[(String, Int, Option[Int])]("USERS") {
    def id = column[Option[Int]]("USER_ID", O.PrimaryKey, O.AutoInc)
    def name = column[String]("USER_NAME", O.NotNull)
    def pictureId = column[Int]("PIC_ID", O.NotNull)
    def * = name ~ pictureId ~ id
    def justNameAndPicId = name ~ pictureId <> (UserAndPicId, UserAndPicId.unapply _)

    private def autoInc(implicit session: Session) = name ~ pictureId returning id into {
      case (_, id) => id
    }

    def insert(user: User)(implicit session: Session): User = {
      val picture = if (user.picture.id.isEmpty) { //if no picture id...
        Pictures.insert(user.picture) //...insert
      } else user.picture //else return current picture

      val id = autoInc.insert(user.name, picture.id.get)
      user.copy(picture = picture, id = id)
    }

    def userAndPicById = for {
      id <- Parameters[Int]
      user <- this if user.id === id
    } yield justNameAndPicId
  }
}

/**
 * The Data Access Layer contains all components and a profile
 */
class DAL(override val profile: ExtendedProfile) extends UserComponent with PictureComponent with Profile {
  import profile.simple._
  def create(implicit session: Session): Unit = {
    (Users.ddl ++ Pictures.ddl).create //helper method to create all tables
  }
}

/**
 * Run SLICK code with multiple DBMSs using the Cake pattern.
 * Typically this technique can be used to have different DBMS 
 * in production and test (other scenarios are possible as well)
 */
object MultiDBCakeExample {
  // We only need the DB/session imports outside the DAL
  import scala.slick.session.{ Database, Session }

  def run(name: String, dal: DAL, db: Database) {
    import dal._
    import dal.profile.simple._

    println("Running test against " + name)
    db withSession { implicit session: Session =>
      dal.create

      //creating our default picture
      val defaultPic = Pictures.insert(Picture("http://pics/default"))
      println("  Inserted picture: " + defaultPic)

      //inserting users
      val (user1, user2, user3) = (User("name1", defaultPic), User("name2", Picture("http://pics/2")), User("name3", defaultPic))
      println("  Inserted user: " + Users.insert(user1))
      println("  Inserted user: " + Users.insert(user2))
      println("  Inserted user: " + Users.insert(user3))
      println("  All pictures: " + Query(Pictures).list)
      println("  All users : " + Query(Users).list)

      println("  Attempting to fetch UserAndPicId by id")
      Users.userAndPicById(1).firstOption
    }
  }

  def main(args: Array[String]) {
    run("H2", new DAL(H2Driver),
      Database.forURL("jdbc:h2:mem:test1", driver = "org.h2.Driver"))
    run("SQLite", new DAL(SQLiteDriver),
      Database.forURL("jdbc:sqlite::memory:", driver = "org.sqlite.JDBC"))
  }
}
4

1 に答える 1

0

問題はここにあります：

def userAndPicById = for {
  id <- Parameters[Int]
  user <- this if user.id === id
} yield justNameAndPicId

使用できませんthis。を使用しQuery(Users)ます。

于 2013-04-15T16:43:02.450 に答える