问题描述
我有一个数据帧,我希望将数据汇总到7天做一些聚集上的一些功能。
I have a data frame and I want to roll up the data into 7days and do some aggregation on some of the function.
我有一个pyspark SQL数据帧像------
I have a pyspark sql dataframe like ------
Sale_Date|P_1|P_2|P_3|G_1|G_2|G_3|Total_Sale|Sale_Amt|Promo_Disc_Amt |
|2013-04-10| 1| 9| 1| 1| 1| 1| 1| 295.0|0.0|
|2013-04-11| 1| 9| 1| 1| 1| 1| 3| 567.0|0.0|
|2013-04-12| 1| 9| 1| 1| 1| 1| 2| 500.0|200.0|
|2013-04-13| 1| 9| 1| 1| 1| 1| 1| 245.0|20.0|
|2013-04-14| 1| 9| 1| 1| 1| 1| 1| 245.0|0.0|
|2013-04-15| 1| 9| 1| 1| 1| 1| 2| 500.0|200.0|
|2013-04-16| 1| 9| 1| 1| 1| 1| 1| 250.0|0.0|
我已经申请窗口函数在数据帧如下: -
I have applied a window function over the data frame as follows -
days = lambda i: i * 86400
windowSp = Window().partitionBy(dataframeOfquery3["P_1"],dataframeOfquery3["P_2"],dataframeOfquery3["P_3"],dataframeOfquery3["G_1"],dataframeOfquery3["G_2"],dataframeOfquery3["G_3"])\
.orderBy(dataframeOfquery3["Sale_Date"].cast("timestamp").cast("long").desc())\
.rangeBetween(-(days(7)), 0)
现在我想执行一些聚集即运用一些窗口功能,如以下 -
Now I want to perform some aggregation i.e. applying some windows functions like the following --
df = dataframeOfquery3.select(min(dataframeOfquery3["Sale_Date"].over(windowSp).alias("Sale_Date")))
df.show()
但它给下面的错误。
But it is giving following error.
py4j.protocol.Py4JJavaError: An error occurred while calling o138.select.
: org.apache.spark.sql.AnalysisException: Could not resolve window function 'min'. Note that, using window functions currently requires a HiveContext;
我使用Apache 1.6.0星火pre-建立在Hadoop的。
I am using Apache Spark 1.6.0 Pre-built on Hadoop.
推荐答案
错误那种说一切:
py4j.protocol.Py4JJavaError: An error occurred while calling o138.select.
: org.apache.spark.sql.AnalysisException: Could not resolve window function 'min'. Note that, using window functions currently requires a HiveContext;
您将需要一个版本火花支持蜂巢(建立与蜂巢)比你可以声明hivecontext:
You'll need a version of spark that supports hive (build with hive) than you can declare a hivecontext :
val sqlContext = new org.apache.spark.sql.hive.HiveContext(sc)
,然后使用该上下文来执行你的窗口的功能。
and then use that context to perform your window function.
在Python中:
# sc is an existing SparkContext.
from pyspark.sql import HiveContext
sqlContext = HiveContext(sc)
您可以约之间的 SQLContext
和 HiveContext
here.
SparkSQL具有SQLContext和HiveContext。 HiveContext是一个超集SQLContext的。星火社区建议使用HiveContext。你可以看到,当您运行火花壳,这就是交互式驱动器的应用,它会自动创建定义为SC和定义为一个sqlContext一个HiveContext SparkContext。该HiveContext允许你执行的SQL查询以及蜂巢命令。对于发生的pyspark相同的行为。
SparkSQL has a SQLContext and a HiveContext. HiveContext is a super set of the SQLContext. The Spark community suggest using the HiveContext. You can see that when you run spark-shell, which is your interactive driver application, it automatically creates a SparkContext defined as sc and a HiveContext defined as sqlContext. The HiveContext allows you to execute SQL queries as well as Hive commands. The same behavior occurs for pyspark.
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