我用的是Flink 1.12
我写了一个简单的flink代码如下，它从StockSource读取股票记录，每个股票由三个字段组成：id,trade_date,price。pt是过程时间。
当我运行下面的sql时，flink抱怨不支持对非时间属性字段进行排序，我想知道问题出在哪里。
sql为：

val sql =
    """
      select  pt, sum(price) from sourceTable
      group by  pt
      order by pt

      """.stripMargin(' ')

    tenv.sqlQuery(sql).toRetractStream[Row].print()

Flink 代码为：

object OrderByProctime {
  
   def main(args: Array[String]) {
    val env = StreamExecutionEnvironment.getExecutionEnvironment
    env.setStreamTimeCharacteristic(TimeCharacteristic.EventTime)
    env.setParallelism(1)
    val ds: DataStream[Stock] = env.addSource(new StockSource())
    val tenv = StreamTableEnvironment.create(env)
    tenv.createTemporaryView("sourceTable", ds, $"id", $"price", $"pt".proctime())

    //ERROR：
    //Sort on a non-time-attribute field is not supported. org.apache.flink.table.api.TableException: Sort on a non-time-attribute field is not supported.
    val sql =
    """
      select  pt, sum(price) from sourceTable
      group by  pt
      order by pt

      """.stripMargin(' ')

    tenv.sqlQuery(sql).toRetractStream[Row].print()

    env.execute()
  }
}