通常会创建这样的自定义ID:
case class CustomID(value: Int) extends MappedTo[Int]
并使用Option [CustomID]等类型表示可空的自定义ID。但是,我希望能够将Option [_]移动到case类中,如下所示:
case class OptCustomID(optValue: Option[Int])
更具体地说,我正在寻找一个TypedType [OptCustomId],其行为类似于内置的TypedType [Option [Int]],与数据库DDL有关。
有任何想法吗?
其实你不需要TypedType[OptCustomId]
。在页面OptCustomID
中描述了处理具有http://slick.lightbend.com/doc/3.3.0/userdefined.html类型字段的表的正确方法
import slick.jdbc.PostgresProfile.api._
case class OptCustomID(optValue: Option[Int])
case class LiftedOptCustomID(optValue: Rep[Option[Int]])
implicit object OptCustomIDShape extends CaseClassShape(LiftedOptCustomID, OptCustomID)
case class Thing(id: OptCustomID, data: String)
case class LiftedThing(id: LiftedOptCustomID, data: Rep[String])
implicit object ThingShape extends CaseClassShape(LiftedThing.tupled, Thing.tupled)
class ThingTable(tag: Tag) extends Table[Thing](tag, "things") {
def id = column[Option[Int]]("id", O.PrimaryKey)
def data = column[String]("data")
def * = LiftedThing(LiftedOptCustomID(id), data)
}
val things = TableQuery[ThingTable]
val result: DBIO[Option[Thing]] = things.filter(x => x.id === 1).result.headOption