scala - 对同一张 table 使用光滑的多重投影

Question

我有一个用户表，我想对其进行多个投影。例如，我可以有类似的东西吗

class Users(tag: Tag) extends Table [User] (tag, "user") {
def * = (id.?, emailId, firstName, lastName, gender) <> (User.tupled, User.unapply)
def allDetails = (id.?, emailId, firstName, lastName, gender, createdTime, modifiedTime)
...
}

我在谷歌上搜索，但找不到任何东西。有人可以告诉我如何使用 allDetails 吗？

我愿意做

object Users  {
  val users = TableQuery[Users]
  def getAllDetails = ??? // How can I use allDetails here
  }

Answer 1

最近有同样的需求，并开始使用类似的东西:

abstract class AnyUserTable[T](tag: Tag) extends Table[T](tag, "user") {
    def id = column[Int]("id", O.PrimaryKey, O.AutoInc)
    def emailId = column[String]("email_id")
    def firstName = column[String]("firstname")
    def lastName = column[String]("lastname")
    def gender = column[String]("gender")
}

class Users(tag: Tag) extends AnyUserTable[User](tag) {
    def * = (emailId, firstName, lastName, gender, id.?) <> (User.tupled, User.unapply)
}

class UserDetails(tag: Tag) extends AnyUserTable[UserDetail](tag) {
    def createdTime = column[Option[Timestamp]]("created_time")
    def modifiedTime = column[Option[Timestamp]]("modified_time")
    def * = (emailId, firstName, lastName, gender, createdTime, modifiedTime, id.?) <> (UserDetail.tupled, UserDetail.unapply)
}

object Users  {
    val users = TableQuery[Users]
    val getAllDetails = TableQuery[UserDetails] // That is how I propose to get all the details
}

从 Sky 的答案中借用案例类。

case class User(
    emailId: String, firstName: String, lastName: String,
    gender: String, id: Option[Int] = None)

case class UserDetail(
    emailId: String,
    firstName: String, lastName: String, gender: String,
    createdTime: Option[Timestamp],
    modifiedTime: Option[Timestamp], id: Option[Int] = None)

我想这与我在直接 sql 中使用可更新 View 所做的非常接近。