使用Scala中的Slick库获取自动增量值

Question

如何获取使用Slick插入的记录的自动递增值？下面的代码打印1111.我原本预计它会打印1234

import scala.slick.driver.H2Driver.simple._

object TestMappedTable extends App{
    case class User(id: Option[Int], first: String, last: String)

    object Users extends Table[User]("users") {
        def id = column[Int]("id", O.PrimaryKey, O.AutoInc)
        def first = column[String]("first")
        def last = column[String]("last")
        def * = id.? ~ first ~ last <> (User, User.unapply _)
    }

  implicit val session = Database.forURL("jdbc:h2:mem:test1", driver = "org.h2.Driver").createSession()
  session.withTransaction{
    Users.ddl.create

    print(Users.insert(User(None, "Jack", "Green" )))
    print(Users.insert(User(None, "Joe", "Blue" )))
    print(Users.insert(User(None, "John", "Purple" )))
    print(Users.insert(User(None, "Jim", "Yellow" )))
  }
}

我正在使用Slick 0.11.2 for Scala 2.10.0-RC1

Answer 1

您可以像这样检索生成的值.

将autoInc方法添加到Users对象.

def autoInc = id.？~first~last <>(User,User.unapply _)返回id

请Users.autoInc.insert改用.

print(Users.autoInc.insert(User(None,"Jack","Green")))

也可以看看:

https://github.com/slick/slick/issues/10

https://github.com/slick/slick/commit/09a65a8e88a0363412e218dc5c06023b69809649

Answer 2

最新版本的Slick(2.1.0)会自动忽略自动递增的ID,文档演示了如何检索id:

val userWithId =
  (users returning users.map(_.id)
         into ((user,id) => user.copy(id=Some(id)))
  ) += User(None, "Stefan", "Zeiger")

这是完整的monty,然后将检索到的值插回到要添加到表中的对象中.如果你只是想亲自动手身份:

val userId =
  (users returning users.map(_.id)) += User(None, "Stefan", "Zeiger")

这两个代码片段都来自官方文档.看起来这个问题需要更新给那些从未使用早期版本的Slick的新手(比如我).