2

我正在尝试在过滤器中使用日期时间的 Column[DateTime]，但只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，我收到以下错误：

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？

4

2 回答 2

1

在 Slick里面filter,map等你只能使用可以翻译成 SQL 的代码；显然它不能使用任意的 Java/Scala 类，比如DateTimeComparatoror DateTimeWrapper。Slick目前似乎不支持日期时间比较；你可能想看这个问题。另请参阅Slick: Filtering all records which has a joda DateTime date equal to today。

于 2014-10-20T05:20:52.107 回答
0

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

于 2014-11-19T06:58:32.977 回答