Scala Slick泛型表特性移出DAO

Question

我现在有这个代码:

class UsersRepository @Inject()(protected val dbConfigProvider: DatabaseConfigProvider) extends HasDatabaseConfigProvider[JdbcProfile] {
  import driver.api._
  private val Users = TableQuery[UsersTable]
  def findByName(name: String): Future[Option[User]] =
    db.run(Users.filter(_.name === name).take(1).result.headOption)
  implicit val localDateTimeColumnType = MappedColumnType.base[LocalDateTime, Timestamp](
    d => Timestamp.from(d.toInstant(ZoneOffset.ofHours(0))),
    d => d.toLocalDateTime
  )
  trait GenericTable {
    this: Table[_] =>
    def id = column[Long]("id", O.PrimaryKey, O.AutoInc)
    def createdAt = column[LocalDateTime]("created_at")
    def updatedAt = column[LocalDateTime]("updated_at")
  }
  private class UsersTable(tag: Tag) extends Table[User](tag, "User") with GenericTable {
    def name = column[String]("name")
    def url = column[String]("url")
    def nameIndex = index("name_index", name, unique = true)
    override def * = (id, createdAt, updatedAt, name, url) <> (User.tupled, User.unapply)
  }
}

我现在怎么能很容易地移动GenericTable trait的UsersRepository，以便我可以使用它与其他表?如果我只是把它移出来，那么像column, Table和O这样的东西就找不到了，因为我从驱动程序导入中丢失了东西。

我还想将UsersTable定义本身移出DAO/存储库类。在这种情况下我也有同样的问题。

谢谢,马格努斯

Answer 1

提供者dbConfig在trait中作为无输入参数def

trait GenericTableProvider {
  val dbConfig: DatabaseConfig[JdbcProfile]
  import dbConfig.driver.api._
  trait GenericTable {
      this: Table[_] =>
      def id = column[Long]("id", O.PrimaryKey, O.AutoInc)
      def createdAt = column[LocalDateTime]("created_at")
      def updatedAt = column[LocalDateTime]("updated_at")
    }
}

，然后使用它，如下面的代码片段所示。

class UsersRepository @Inject()(protected override val dbConfigProvider: DatabaseConfigProvider) 
  extends HasDatabaseConfigProvider[JdbcProfile] 
  with GenericTableProvider {
  import driver.api._
  private val Users = TableQuery[UsersTable]
  private class UsersTable(tag: Tag) extends Table[User](tag, "User") with GenericTable {
    def name = column[String]("name")
    def url = column[String]("url")
    def nameIndex = index("name_index", name, unique = true)
    override def * = (id, createdAt, updatedAt, name, url) <> (User.tupled, User.unapply)
  }
  .....
 }

用val dbConfigProvider重写def dbConfigProvider