Question

我正在使用带有Scala Play框架2.6的slick 3.2.3。我正在通过迭代将行插入表中。它有时会成功保存，但有时会在MYSQL中保存几行（缺少某些行）。什么可能是根本原因？ MYSQL版本-5.7 这是我的代码

try {
      db.run {
        documentDetails.map(p => (p.documentDetailsId, p.documentDirectoryId, p.patentId, p.hospitalId, p.clinicId, p.patientType, p.categoryType, p.admissionAppointmentNo, p.documentName, p.status, p.remarks, p.description)) += (docId, documentDirectoryId, patentId, hospitalId, clinicId, patientType, categoryType, admissionAppointmentNo, documentName, true, remarks, description)
      }
    }
    catch {
      case e: Exception =>
        e.printStackTrace()
        logger.error(e.getMessage)
        throw e
    }

Answer 1

db.run返回一个Future，因此您应该对此Future进行操作。

顺便说一下，您的try-catch块不会检查未来是否失败。

尝试

Await.result(db.run(...), Duration.Inf)

如果您认为屏蔽是可以的（取决于此代码的位置）。

Answer 2

我想最好在DBIO或Future中检查 rowsAffected ...

文档：（受影响的行）

/** Insert multiple rows, skipping AutoInc columns.
      * Uses JDBC's batch update feature if supported by the JDBC driver.
      * Returns Some(rowsAffected), or None if the database returned no row
      * count for some part of the batch. If any part of the batch fails, an
      * exception is thrown. */
    def ++= (values: Iterable[U]): ProfileAction[MultiInsertResult, NoStream, Effect.Write]

因此在DBIO中：

      /**
        *
        * @param f function throws exception
        * @return DBIO.successful --> is good!!!
        *         DBIO.failed(th) --> is bad :-(
        */
      def validate(f: => Unit): DBIOAction[Unit, NoStream, Effect] = try {
        DBIO.successful(f)
      } catch {
        case NonFatal(th) => DBIO.failed(ValidationError(th))
      }

      def checkRowsAffected(rowsAffect: Int, rowsAffected: Int,
        errorMessage: String = "rowAffected not equal rowsAffect"): DBIOAction[Unit, NoStream, Effect] =
        validate(require(rowsAffect == rowsAffected, errorMessage))

      val BannersInsertQuery = Banners returning Banners.map(_.id)

       for {
           bannersInserted <- BannersInsertQuery ++= bannersToInsert
           _ <- checkRowsAffected(bannersToInsert.length, bannersInserted.length)
       } yield bannersInserted

因此将来：（使用db.run）

/**
    *
    * @param f function throws exception
    * @return Future.successful --> is good!!!
    *         Future.failed(ex) --> is bad :-(
    */
  def validate(f: => Unit)(implicit ec: ExecutionContext): Future[Unit] = Future.successful(f).recover {
    case ve: ValidationError => Future.failed(ve)
    case NonFatal(th)        => Future.failed(ValidationError(th))
  }

  def checkRowsAffected(rowsAffect: Int, rowsAffected: Int,
                        errorMessage: String = "rowAffected not equal rowsAffect")
                       (implicit ec: ExecutionContext): Future[Unit] =
    validate(require(rowsAffect == rowsAffected, errorMessage))


db.run(BannersInsertQuery ++= bannersToInsert).map( bannersInserted => checkRowsAffected(bannersToInsert.length, bannersInserted.length))

光滑表未保存在数据库中，没有错误

2 个答案: