来自任何其他类的光滑过滤器

Question

我有一个案例类，映射和像这样定义的对象

import slick.driver.PostgresDriver.api._

import scala.concurrent.Await
import scala.concurrent.duration.Duration

case class Coffee(name : String, supID: Int, price: Double, sales: Int, total: Int) {

  def save(): Coffee = { Coffees.save(this) }

  def delete() { Coffees.delete(this) }
}

class Coffees(tag: Tag) extends Table[Coffee](tag, "coffee") {
  def name = column[String]("cof_name", O.PrimaryKey)
  def supID = column[Int]("sup_id")
  def price = column[Double]("price")
  def sales = column[Int]("sales", O.Default(0))
  def total = column[Int]("total", O.Default(0))
  def * = (name, supID, price, sales, total) <> (Coffee.tupled, Coffee.unapply)
}

object Coffees extends TableQuery(new Coffees(_)) {
  lazy val db = DatabaseAccess.databases("db.test")
  def save(coffee: Coffee): Coffee = {
    val saveQuery = (this returning this).insertOrUpdate(coffee)
    Await.result(db.run(saveQuery), Duration.Inf) match {
      case Some(x) => x
      case None => coffee
    }
  }

  def delete(coffee: Coffee) = {
    Await.result(db.run(this.filter(_.name === coffee.name).delete), Duration.Inf)
  }
}

现在我想编写其他类的查询：

import com.typesafe.config.ConfigFactory
import org.scalatest.{FeatureSpec, GivenWhenThen, Matchers}

class CoffeeSpec extends FeatureSpec with GivenWhenThen with Matchers {
  feature("Accessing coffees in the database") {
    scenario("Adding a new coffee") {
      val config = ConfigFactory.load()
      DatabaseAccess.loadConfiguration(config)
      lazy val db = DatabaseAccess.databases("db.test")

      val coffee = Coffee("nescafe", 1, 20, 20, 40).save()

      val temp = Coffees.filter(_.name === "nescafe")

      temp.length should be (1)

      coffee.delete()
    }
  }
}

这一行

val temp = Coffees.filter(_.name === "nescafe")

引发如下错误：

在Coffees对象上编写过滤器查询的最佳方法是什么？ 使用slick 2.0我有类似的查询：

Query(Coffees).filter(_.name is "coffee").firstOption.getOrElse(None)

我希望能够使用新设置对所有数据映射执行类似的查询。

为什么我会收到这些错误？我应该如何在光滑的3中进行类似的查询？

Answer 1

您的查询没问题，但您的CoffeeSpec文件缺少导入：

import slick.driver.PostgresDriver.api._

编译应该通过。