Question

我尝试使用过滤器中的日期时间列[DateTime]，但是无法弄清楚如何使其工作。

import play.api.Play.current
import play.api.db.slick.Config.driver.simple._
import play.api.db.slick._
import org.joda.time.{DateTime, DateTimeComparator, DateTimeZone}

  private val dateComparator = DateTimeComparator.getInstance()

  implicit def dateTimeToScalaWrapper(dt: DateTime): DateTimeWrapper = new DateTimeWrapper(dt)

  class DateTimeWrapper(dt: DateTime) extends Ordered[DateTime] with Ordering[DateTime] {
    def compare(that: DateTime): Int = dateComparator.compare(dt, that)
    def compare(a: DateTime, b: DateTime): Int = dateComparator.compare(a, b)
  }

  implicit def jodaType = MappedColumnType.base[DateTime, Timestamp](
  {d => new Timestamp(d.getMillis)} ,
  {d => new DateTime(d.getTime, UTC)}
  )

  def removeTimeSlots(start: DateTime, end: DateTime, reservationId: Long) : Int = DB withTransaction { implicit session =>
    timeSlots.filter(x => x.reservationId == reservationId && x.startTime >= start && x.starTime <= end).delete
  }

在我比较x.startTime并开始时，我得到以下错误：

Error:(90, -1) Play 2 Compiler: 
Reservations.scala:90: polymorphic expression cannot be instantiated to expected type;
  found   : [R]scala.slick.lifted.Column[R]
  required: Boolean

我有机会在我的代码中进行这些比较吗？

Answer 1

在Slick中的filter，map等内部，您只能使用可以转换为SQL的代码;很明显，它不能使用像DateTimeComparator或DateTimeWrapper这样的任意Java / Scala类。光滑doesn't seem to support datetime comparison currently;你可能想看这个问题。另请参阅Slick: Filtering all records which have a joda DateTime date equal to today。

Answer 2

这个jodatime映射器对Play非常有用！：https://github.com/tototoshi/slick-joda-mapper

比较过滤器中的joda.DateTime

2 个答案: