Scala Slick generic table trait 移出 DAO

Question

我目前有这个代码：

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)
  }

}

我现在如何轻松地将 GenericTable 特征从 UsersRepository 中移出，以便我可以将它用于其他表？如果我只是将其移出，那么就不会再找到 column、Table 和 O 之类的东西，因为我从驱动程序导入中丢失了这些东西。

我还想将 UsersTable 定义本身移出 DAO/repository class。我在这种情况下遇到了同样的问题。

谢谢，马格努斯

Answer 1

Trait 中的 Provider dbConfig 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")
    }

}

然后按照下面的代码片段所示使用它。

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

覆盖 def dbConfigProvider

Scala Slick generic table trait 移出 DAO

Scala Slick generic table trait move out of DAO

scala

playframework

slick