Spark Scala数据框具有单个Group By的多个聚合

本文介绍了Spark Scala数据框具有单个Group By的多个聚合的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

Spark Scala数据帧具有单个group by的多个聚合.例如

Spark Scala Data Frame to have multiple aggregation of single group by. eg

val groupped = df.groupBy("firstName", "lastName").sum("Amount").toDF()

但是如果我需要计数，总和，最大值等

But What if I need Count, Sum, Max etc

/* Below Does Not Work , but this is what the intention is val groupped = df.groupBy("firstName", "lastName").sum("Amount").count().toDF() */

输出 groupped.show()

-------------------------------------------------- | firstName | lastName| Amount|count | Max | Min | --------------------------------------------------

推荐答案

case class soExample(firstName: String, lastName: String, Amount: Int) val df = Seq(soExample("me", "zack", 100)).toDF import org.apache.spark.sql.functions._ val groupped = df.groupBy("firstName", "lastName").agg( sum("Amount"), mean("Amount"), stddev("Amount"), count(lit(1)).alias("numOfRecords") ).toDF() display(groupped)