18

我正在使用带有播放框架 2.1.0 的 Slick 1.0.0。Users查询表时出现以下错误。的值LOGIN_ID在 DB 中为空。我正在执行的查询是：

    val user = { for { u <- Users if u.providerId === id.id } yield u}.first

这会导致以下错误：

play.api.Application$$anon$1: Execution exception[[SlickException: Read NULL value for column (USERS /670412212).LOGIN_ID]]
    at play.api.Application$class.handleError(Application.scala:289) ~[play_2.10.jar:2.1.0]
    at play.api.DefaultApplication.handleError(Application.scala:383) [play_2.10.jar:2.1.0]
    at play.core.server.netty.PlayDefaultUpstreamHandler$$anonfun$12$$anonfun$apply$24.apply(PlayDefaultUpstreamHandler.scala:314) [play_2.10.jar:2.1.0]
    at play.core.server.netty.PlayDefaultUpstreamHandler$$anonfun$12$$anonfun$apply$24.apply(PlayDefaultUpstreamHandler.scala:312) [play_2.10.jar:2.1.0]
    at play.api.libs.concurrent.PlayPromise$$anonfun$extend1$1.apply(Promise.scala:113) [play_2.10.jar:2.1.0]
    at play.api.libs.concurrent.PlayPromise$$anonfun$extend1$1.apply(Promise.scala:113) [play_2.10.jar:2.1.0]
scala.slick.SlickException: Read NULL value for column (USERS /670412212).LOGIN_ID
    at scala.slick.lifted.Column$$anonfun$getResult$1.apply(ColumnBase.scala:29) ~[slick_2.10-1.0.0.jar:1.0.0]
    at scala.slick.lifted.TypeMapperDelegate$class.nextValueOrElse(TypeMapper.scala:158) ~[slick_2.10-1.0.0.jar:1.0.0]
    at scala.slick.driver.BasicTypeMapperDelegatesComponent$TypeMapperDelegates$StringTypeMapperDelegate.nextValueOrElse(BasicTypeMapperDelegatesComponent.scala:146) ~[slick_2.10-1.0.0.jar:1.0.0]
    at scala.slick.lifted.Column.getResult(ColumnBase.scala:28) ~[slick_2.10-1.0.0.jar:1.0.0]
    at scala.slick.lifted.Projection15.getResult(Projection.scala:627) ~[slick_2.10-1.0.0.jar:1.0.0]
    at scala.slick.lifted.Projection15.getResult(Projection.scala:604) ~[slick_2.10-1.0.0.jar:1.0.0]

我的用户表定义为：

package models

import scala.slick.driver.MySQLDriver.simple._

case class User(userId:String,email:String,loginId:String,fullName:String,firstName:String,lastName:String,location:String,homeTown:String,providerId:String,provider:String,state:String,zip:String,accessKey:String,refreshKey:String,avatarUrl:String)

object Users extends Table[User]("USERS") {
  def userId = column[String]("USER_ID", O.PrimaryKey) // This is the primary key column
  def email =  column[String]("EMAIL",O.NotNull)
  def loginId = column[String]("LOGIN_ID",O.Nullable)
  def fullName = column[String]("FULL_NAME",O.NotNull)
  def firstName = column[String]("FIRST_NAME",O.Nullable)
  def lastName = column[String]("LAST_NAME",O.Nullable)
  def location = column[String]("LOCATION",O.Nullable)
  def homeTown = column[String]("HOME_TOWN",O.Nullable)
  def providerId = column[String]("PROVIDER_ID",O.Nullable)
  def provider = column[String]("PROVIDER",O.Nullable)
  def state = column[String]("STATE",O.Nullable)
  def zip = column[String]("ZIP",O.Nullable)
  def accessKey = column[String]("ACCESS_KEY",O.Nullable)
  def refreshKey = column[String]("REFRESH_KEY",O.Nullable)
  def avatarUrl = column[String]("AVATAR_URL",O.Nullable)

  // Every table needs a * projection with the same type as the table's type parameter
  def * = userId ~ email ~ loginId ~ fullName ~ firstName ~ lastName ~ location ~ homeTown ~ providerId ~ provider ~ state ~ zip ~ accessKey ~ refreshKey ~ avatarUrl <> (User,User.unapply _)
}

请帮忙。看起来 Slick 无法处理来自 DB 的 Null 值？

4

4 回答 4

28

你的案例课不行。如果你使用O.Nullable，你的所有属性都必须是 Option[String]。

于 2013-03-31T17:47:37.207 回答
6

如果您收到此错误，您将不得不创建 properties O.Nullable，或者您必须指定您的查询返回一个选项。

例如，假设rightJoin您可能不想将正确记录的属性设为可选。在这种情况下，您可以使用自定义生成结果的方式.?

val results = (for {
  (left, right) <- rightRecord.table rightJoin leftRecord.table on (_.xId === _.id)
  } yield (rightRecord.id, leftRecord.name.?)).list
results map (r => SomeJoinedRecord(Some(r._1), r._2.getOrElse(default)))
于 2014-06-24T13:02:36.503 回答
3

如果列包含空值并且在运行时它在列响应中获得空值，则会出现此问题。如果您在下面的代码中看到，我的 cust_id 可以为空，但它没有空值。因为，有一项工作可以确保它永远不会为空。因此，以下映射有效。但是，最好查看表结构并相应地创建类。这避免了讨厌的运行时异常。

如果数据库上的表定义如下：

CREATE TABLE public.perf_test (
    dwh_id serial NOT NULL,
    cust_id int4 NULL,
    cust_address varchar(30) NULL,
    partner_id int4 NULL,
    CONSTRAINT perf_test_new_dwh_id_key UNIQUE (dwh_id)
);

对应的类定义如下。但是，建议将 cust_id 也设置为Option[Int]. 但是，只要它有值且没有空值，就不会遇到错误。

导入 slick.jdbc.PostgresProfile.api._

class PerfTest(tag: Tag) extends Table[(Int, Int, Option[String], Option[Int])](tag, "perf_test") {
  def dwhId = column[Int]("dwh_id")
  def custId = column[Int]("cust_id")
  def custAddress = column[Option[String]]("cust_address")
  def partnerId = column[Option[Int]]("partner_id")
  def * = (dwhId, custId, custAddress,partnerId)
}
于 2018-10-09T08:38:34.653 回答
0

发生在我身上的是我在数据库中有异常，一些值意外地为空 - 那些我没想到的。所以也不要忘记检查您的数据:)

于 2019-11-05T11:33:49.097 回答