bill of parts/heirarchial queries

gistfile1.txt

// Slick 2.x / play 2.4 
final def managementTree()(implicit  session:Session):Set[String] = {
    managerTreeIter(Set(this.login.toLowerCase))
  }
  @tailrec
  private  def managerTreeIter(acc:Set[String])(implicit  session:Session):Set[String] = {
    this.manager match {
      case None => acc
      case Some(mgr) => mgr.managerTreeIter(  acc ++Set( mgr.login.toLowerCase))
    }
  }
  
  // ** Slick 3.2.X / play 2.6 **
def managementTreeUp(login:String):Future[Set[EmprelationsRow]] = {
    def managementTreeUpI(login: String, acc: Future[Set[EmprelationsRow]]): Future[Set[EmprelationsRow]] = {
      manager(login.toLowerCase).map {
        case Some(m) => managementTreeUpI(m.login, acc.map { setMgr => setMgr ++ Set(m) })
        case None => acc
      }.flatMap(identity)
    }
    managementTreeUpI(login, Future(Set.empty))
  }

manager function is
def manager(login:String): Future[Option[EmprelationsRow]] = {
val qry = (for {
emp <- Emprelations if emp.login === login.toLowerCase
mgr <- Emprelations if mgr.login === emp.managerid
} yield mgr).result.headOption
db.run(qry)
}