Question

abstract class AbstractDBService[Mixin, RTable <: Table[_ <: AbstractRecord[Mixin]] with AbstractTable[AbstractRecord[Mixin]], NewTable <: Table[_ <: AbstractRecord[Mixin]] with AbstractNewTable[AbstractNewRecord[Mixin]]](override protected val dbConfigProvider: DatabaseConfigProvider)(implicit executionContext: ExecutionContext)
  extends AbstractBaseDBService[Mixin, RTable, NewTable](dbConfigProvider) {


  def create(newRecord: NewTable#TableElementType): Future[Option[RTable#TableElementType]] = db.run(
    ((newRecords returning records) += newRecord).asTry map {
      case Success(record) => Some(record)
      case Failure(_) => None
    }
  )

  def update(record: RTable#TableElementType): Future[Int] = db.run(
    records.filter(_.id === record.id).update(record)
  )
}

我正在尝试使用scala和slick使通用数据库服务正常工作。上面给了我以下类型错误。

type mismatch;
 found   : newRecord.type (with underlying type _$2)
 required: _$2
    ((newRecords returning newRecords) += newRecord).asTry

和

type mismatch;
 found   : _$1
 required: RTable#TableElementType
    (which expands to)  _$1
    records.filter(_.id === record.id).update(record)

如您所见，类型实际上是一致的，所以我不确定是什么导致了此错误。

以下内容是在超类中定义的

protected val records: TableQuery[RTable]
protected val newRecords: TableQuery[NewTable]

任何帮助将不胜感激

Scala错误类型与泛型中的通配符参数不匹配

0 个答案: