Question

我有一个枚举类型ResourceType，我试图使用光滑的API将其作为Int存储在数据库中。我已经为ResourceType定义了一个自定义类型映射器，但是在我的表定义中我得到了一个编译器错误，说明“找不到匹配的形状.Slick不知道如何映射给定的类型。”。是否有可能使这项工作？

import scala.slick.driver.H2Driver.simple._

case class Resource(val id : Option[Int], val creationDate : Date, val title : String, val resourceType : ResourceType, val description : String) {
}

case class ResourceType private(val databaseCode : Int, val label : String) {
}

object ResourceType {
  val lessonPlan = new ResourceType(1, "Lesson Plan")
  val activity = new ResourceType(2, "Activity")

  val all = scala.collection.immutable.Seq(lessonPlan, activity)

  private val _databaseCodeMap = all.map(t => t.databaseCode -> t).toMap

  def apply(databaseCode : Int) = _databaseCodeMap(databaseCode)
}

class ResourceTable(tag : Tag) extends Table[Resource](tag, "Resource") {
  def id = column[Option[Int]]("ID", O.PrimaryKey, O.AutoInc)
  def creationDate = column[Date]("CreationDate")
  def title = column[String]("Title")
  def resourceType = column[Int]("ResourceType")
  def description = column[String]("Description")

  implicit val resourceTypeTypeMapper = MappedColumnType.base[ResourceType, Int](_.databaseCode, ResourceType(_))

  //Compile error on this line
  def * = (id, creationDate, title, resourceType, description) <> (Resource.tupled, Resource.unapply)
}

Answer 1

resourceType列需要包含ResourceType类型。所以试试

def resourceType = column[ResourceType]("ResourceType")

您可能必须在列定义上方隐式移动类型映射器。

光滑表定义中的自定义映射列类型

1 个答案: