I have came across one issue is Spark sql aggregation. I have one dataframe from which I'm loading records from apache phoenix.
val df = sqlContext.phoenixTableAsDataFrame(
Metadata.tables(A.Test), Seq("ID", "date", "col1", "col2","col3"),
predicate = Some("\"date\" = " + date), zkUrl = Some(zkURL))
In another dataframe I need to aggregate on the basis of ID and date and then sum col1, col2, col3, i.e.
val df1 = df.groupBy($"ID", $"date").agg(
sum($"col1" + $"col2" + $"col3").alias("col4"))
But I'm getting incorrect result while doing the sum. How we can sum all the columns (col1, col2, col3) and assign it to col4?
Example:
Suppose if data is like this:
ID,date,col1,col2,col3
1,2017-01-01,5,10,12
2,2017-01-01,6,9,17
3,2017-01-01,2,3,7
4,2017-01-01,5,11,13
Expected output:
ID,date,col4
1,2017-01-01,27
2,2017-01-01,32
3,2017-01-01,12
4,2017-01-01,29
I get a correct result with this code:
import org.apache.spark.rdd.RDD
import org.apache.spark.sql.{DataFrame, Row}
import org.apache.spark.sql.functions.{col, sum}
import org.apache.spark.sql.types.{IntegerType, StructField, StructType}
val rowsRdd: RDD[Row] = spark.sparkContext.parallelize(
Seq(
Row(1, 1, 5, 10, 12 ),
Row(2, 1, 6, 9, 17 ),
Row(3, 1, 2, 3, 7),
Row(4, 1, 5, 11, 13)
)
)
val schema: StructType = new StructType()
.add(StructField("id", IntegerType, false))
.add(StructField("date", IntegerType, false))
.add(StructField("col1", IntegerType, false))
.add(StructField("col2", IntegerType, false))
.add(StructField("col3", IntegerType, false))
val df0: DataFrame = spark.createDataFrame(rowsRdd, schema)
val df = df0.groupBy(col("id"), col("date")).agg(sum(col("col1") + col("col2") + col("col3")).alias("col4")).sort("id")
df.show()
Result is:
+---+----+----+
| id|date|col4|
+---+----+----+
| 1| 1| 27|
| 2| 1| 32|
| 3| 1| 12|
| 4| 1| 29|
+---+----+----+
Is this what you need?