Question

尝试与桑格利亚汽酒和Slick合作。他们俩都是新手。

我有一堆共享公用字段列表的表。 Slick对此的表示如下：

case class CommonFields(created_by: Int = 0, is_deleted: Boolean = false)

trait CommonModel {
  def commonFields: CommonFields
  def created_by = commonFields.created_by
  def is_deleted = commonFields.is_deleted
}

case class User(id: Int,
                name: String,
                commonFields: CommonFields = CommonFields()) extends CommonModel

光滑的桌子

  abstract class CommonTable [Model <: CommonModel] (tag: Tag, tableName: String) extends Table[Model](tag, tableName) {
    def created_by = column[Int]("created_by")
    def is_deleted = column[Boolean]("is_deleted")
  }

  case class CommonColumns(created_by: Rep[Int], is_deleted: Rep[Boolean])

  implicit object CommonShape extends CaseClassShape(
    CommonColumns.tupled, CommonFields.tupled
  )

  class UsersTable(tag: Tag) extends CommonTable[User](tag, "USERS") {
    def id = column[Int]("ID", O.PrimaryKey, O.AutoInc)
    def name = column[String]("NAME")

    def * = (id,
      name,
      CommonColumns(created_by, is_deleted)) <> (User.tupled, User.unapply)
  }

  val Users = TableQuery[UsersTable]

问题出在Graphql上：

 lazy val UserType: ObjectType[Unit, User] = deriveObjectType[Unit, User]()

当我尝试使用namedObjectType宏创建UserType时，它抱怨

Can't find suitable GraphQL output type for <path>.CommonFields. If you have defined it already, please consider making it implicit and ensure that it's available in the scope.
                       [error]   lazy val UserType: ObjectType[Unit, User] = deriveObjectType[Unit, User](

如何告诉Sangria / Graphql如何处理此嵌套字段列表（来自CommonFields）？

请帮助。

Answer 1

您正在派生用户的类型，但用户还具有尚未派生的CommonFields。因此，它无法找到CommonFields的Type信息。两者都派生，并使派生对CommonFields隐含。

implicit val CommonFieldsType: ObjectType[Unit, CommonFields] = deriveObjectType[Unit, CommonFields]     
implicit val UserType: ObjectType[Unit, User] = deriveObjectType[Unit, User]

桑格利亚汽酒：如何处理自定义类型

1 个答案: