为什么我不能在光滑的查询中使用选项

Question

为了节省我必须创建这么多方法,我尝试将Option's传递给我的方法,然后检查是否定义了Option,如果是,则应用过滤器.

def getUsers(locationId: Option[Int], companyId: Int, salary: Option[Int]): List[User] = {
  val query = for {
    u <- users if u.companyId === companyId && (locationId.isDefined && u.locationId === locationId.get) && (salary.isDefined && u.salary >= salary.get)

  }
  query.list()
}

我收到错误说:

polymorphic expression cannot be instantiated to expected type;

IntelliJ errors are expected Boolean actual Column[Boolean].

这种类型的条款在光滑的查询中是不可能的,或者我只是做错了？

Answer 1

我无法告诉你为什么但这会为我编译:

def getUsers(locationId: Option[Int], companyId: Int, salary: Option[Int]): List[User] = {
  val query = for {
    u <- users if u.companyId === companyId && locationId.isDefined && u.locationId === locationId.get && salary.isDefined && u.salary >= salary.get
  } yield(u)
  query.list()
}

请注意,没有括号和你有yield什么,否则返回类型query会Unit.