Apache Zeppelin 不返回聚合数据

Apache Zeppelin not returning aggregate data

我是 运行 Apache Spark 2.0.1 和 Apache Zeppelin 0.6.2。

在 Zeppelin 中,我有以下段落:

val df = sqlContext
  .read
  .format("org.apache.spark.sql.cassandra")
  .options(Map( "table" -> "iot_data2", "keyspace" -> "iot" ))
  .load()

import org.apache.spark.sql.functions.{avg,round}

val ts = $"updated_time".cast("long")

val interval = (round(ts / 3600L) * 3600.0).cast("timestamp").alias("time")

df.groupBy($"a", $"b", $"date_bucket", interval).avg("t").createOrReplaceTempView("iot_avg")

下一段我正在尝试绘制图表,但 avg("t") 的值始终为 0:

%sql
select time,avg("t") as avg_t from ble_temp_avg where a = '${a}' and b = '${b}' group by time order by time

我想我错过了一些非常明显的东西,但我只是不知道它是什么作为新的 Spark 和 Zeppelin 用户。

这在我重写段落后似乎有效:

第一段中:

val df = sqlContext
  .read
  .format("org.apache.spark.sql.cassandra")
  .options(Map( "table" -> "iot_data2", "keyspace" -> "iot" ))
  .load()

import org.apache.spark.sql.functions.{avg,round}

val ts = $"updated_time".cast("long")

val interval = (round(ts / 3600L) * 3600.0).cast("timestamp").alias("time")

df.select($"a", $"b", $"date_bucket", interval, $"t").createOrReplaceTempView("iot_avg")

第二段中:

%sql
select time,avg(t) as avg_t from iot_avg where a = 'test1' and b = 'test2' group by time order by time