Slick 3.0 Insert and then get Auto Increment Value

问题

I have written this code which works perfectly

class Items(tag: Tag) extends Table[Item](tag, "ITEMS") {
  def id = column[Long]("ITEMS_ID", O.PrimaryKey, O.AutoInc)
  def name = column[String]("ITEMS_NAME")
  def price = column[Double]("ITEMS_PRICE")
  def * = (id, name, price) <> ((Item.apply _).tupled, Item.unapply _)
}

object Shop extends Shop{
  val items = TableQuery[Items]
  val db = Database.forConfig("h2mem1")

  def create(name: String, price: Double) : Int = {
    val action = items ++= Seq(Item(0, name, price))
    val future1 = db.run(action)
    val future2 = future1 map {result => 
      result map {x => x}
    }
    Await.result(future2, Duration.Inf).getOrElse(0)
  }
}

This code works but the return value is number of records inserted. But I want to return the value of the AutoInc after the insert has been done.

i did google and found few articles

Slick 3.0.0 AutoIncrement Composite Key

Returning the auto incrementing value after an insert using slick

But somehow these do not answer the question cleanly.

回答1:

Here's the relevant documentation page, according to which, you should construct a query like this:

val insertQuery = items returning items.map(_.id) into ((item, id) => item.copy(id = id))

def create(name: String, price: Double) : Future[Item] = {
  val action = insertQuery += Item(0, name, price)   
  db.run(action)
}

回答2:

Try this one instead:

def create(name: String, price: Double): Future[Int] = db.run {
    (items returning items.map(_.id)) += Item(0, name, price)
}

来源：https://stackoverflow.com/questions/31443505/slick-3-0-insert-and-then-get-auto-increment-value