If I have key,value pairs that compromise item(key) and the sales(value):
bolt 45
bolt 5
drill 1
drill 1
screw 1
screw 2
screw 3
So I want to obtain an RDD where each element is the sum of the values for every unique key:
bolt 50
drill 2
screw 6
My current code is like that:
val salesRDD = sc.textFile("/user/bigdata/sales.txt")
val pairs = salesRDD.map(s => (s, 1))
val counts = pairs.reduceByKey((a, b) => a b)
counts.collect().foreach(println)
But my results get this:
(bolt 5,1)
(drill 1,2)
(bolt 45,1)
(screw 2,1)
(screw 3,1)
(screw 1,1)
How should I edit my code to get the above result?
CodePudding user response:
Java way, hope you can convert this to scala. Looks like you just need a groupby and count
salesRDD.groupBy(salesRDD.col("name")).count();
----- -----
| name|count|
----- -----
| bolt| 50|
|drill| 2|
|screw| 6 |
----- -----
Also, please use Datasets and Dataframes rather than RDDs. You will find it a lot handy