Spark scala groupBy后求和

val goalsDF = Seq(
  ("messi", 2),
  ("messi", 1),
  ("pele", 3),
  ("pele", 1)
).toDF("name", "goals")

goalsDF.show()

+-----+-----+
| name|goals|
+-----+-----+
|messi|    2|
|messi|    1|
| pele|    3|
| pele|    1|
+-----+-----+

import org.apache.spark.sql.functions._

goalsDF
  .groupBy("name")
  .agg(sum("goals"))
  .show()
+-----+----------+
| name|sum(goals)|
+-----+----------+
| pele|         4|
|messi|         3|
+-----+----------+

转自:
https://mungingdata.com/apache-spark/aggregations/