Hi Ted,

That doesn't help neither as one method delegates to another as far as I can see:
def collect_list(columnName: String): Column = collect_list(Column(columnName))

Thanks, Alex

On Mon, Feb 1, 2016 at 5:55 PM, Ted Yu <yuzhihong@gmail.com> wrote:
bq. agg(collect_list("b")

Have you tried:

agg(collect_list($"b")

On Mon, Feb 1, 2016 at 8:50 AM, Alexandr Dzhagriev <dzhagr@gmail.com> wrote:
Hello,

I'm trying to run the following example code:

import org.apache.spark.sql.hive.HiveContext
import org.apache.spark.{SparkContext, SparkConf}
import org.apache.spark.sql.functions._


case class RecordExample(a: Int, b: String)

object ArrayExample {
def main(args: Array[String]) {
val conf = new SparkConf()

val sc = new SparkContext(conf)
val sqlContext = new HiveContext(sc)

import sqlContext.implicits._

val dataset = sc.parallelize(Seq(RecordExample(1, "apple"), RecordExample(2, "orange"))).toDS()

dataset.groupBy($"a").agg(collect_list("b").as[List[String]])

dataset.collect()

}

}

and it fails with the following (please see the whole stack trace below):

 Exception in thread "main" java.lang.ClassCastException: org.apache.spark.sql.types.ArrayType cannot be cast to org.apache.spark.sql.types.StructType


Could please someone point me to the proper way to do that or confirm it's a bug?

Thank you and here is the whole stacktrace:

Exception in thread "main" java.lang.ClassCastException: org.apache.spark.sql.types.ArrayType cannot be cast to org.apache.spark.sql.types.StructType
at org.apache.spark.sql.catalyst.expressions.GetStructField.org$apache$spark$sql$catalyst$expressions$GetStructField$$field$lzycompute(complexTypeExtractors.scala:107)
at org.apache.spark.sql.catalyst.expressions.GetStructField.org$apache$spark$sql$catalyst$expressions$GetStructField$$field(complexTypeExtractors.scala:107)
at org.apache.spark.sql.catalyst.expressions.GetStructField.dataType(complexTypeExtractors.scala:109)
at org.apache.spark.sql.catalyst.analysis.ResolveUpCast$$anonfun$apply$24.applyOrElse(Analyzer.scala:1214)
at org.apache.spark.sql.catalyst.analysis.ResolveUpCast$$anonfun$apply$24.applyOrElse(Analyzer.scala:1211)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$3.apply(TreeNode.scala:243)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$3.apply(TreeNode.scala:243)
at org.apache.spark.sql.catalyst.trees.CurrentOrigin$.withOrigin(TreeNode.scala:53)
at org.apache.spark.sql.catalyst.trees.TreeNode.transformDown(TreeNode.scala:242)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformDown$1.apply(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformDown$1.apply(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$4.apply(TreeNode.scala:265)
at scala.collection.Iterator$$anon$11.next(Iterator.scala:370)
at scala.collection.Iterator$class.foreach(Iterator.scala:742)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1194)
at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:59)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:104)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:48)
at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:308)
at scala.collection.AbstractIterator.to(Iterator.scala:1194)
at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:300)
at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1194)
at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:287)
at scala.collection.AbstractIterator.toArray(Iterator.scala:1194)
at org.apache.spark.sql.catalyst.trees.TreeNode.transformChildren(TreeNode.scala:305)
at org.apache.spark.sql.catalyst.trees.TreeNode.transformDown(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformDown$1.apply(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformDown$1.apply(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$4.apply(TreeNode.scala:265)
at scala.collection.Iterator$$anon$11.next(Iterator.scala:370)
at scala.collection.Iterator$class.foreach(Iterator.scala:742)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1194)
at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:59)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:104)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:48)
at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:308)
at scala.collection.AbstractIterator.to(Iterator.scala:1194)
at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:300)
at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1194)
at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:287)
at scala.collection.AbstractIterator.toArray(Iterator.scala:1194)
at org.apache.spark.sql.catalyst.trees.TreeNode.transformChildren(TreeNode.scala:305)
at org.apache.spark.sql.catalyst.trees.TreeNode.transformDown(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformDown$1.apply(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformDown$1.apply(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$4$$anonfun$apply$9.apply(TreeNode.scala:294)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:245)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:245)
at scala.collection.immutable.List.foreach(List.scala:381)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:245)
at scala.collection.immutable.List.map(List.scala:285)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$4.apply(TreeNode.scala:292)
at scala.collection.Iterator$$anon$11.next(Iterator.scala:370)
at scala.collection.Iterator$class.foreach(Iterator.scala:742)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1194)
at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:59)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:104)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:48)
at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:308)
at scala.collection.AbstractIterator.to(Iterator.scala:1194)
at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:300)
at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1194)
at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:287)
at scala.collection.AbstractIterator.toArray(Iterator.scala:1194)
at org.apache.spark.sql.catalyst.trees.TreeNode.transformChildren(TreeNode.scala:305)
at org.apache.spark.sql.catalyst.trees.TreeNode.transformDown(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformDown$1.apply(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformDown$1.apply(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$4$$anonfun$apply$9.apply(TreeNode.scala:294)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:245)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:245)
at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:48)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:245)
at scala.collection.AbstractTraversable.map(Traversable.scala:104)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$4.apply(TreeNode.scala:292)
at scala.collection.Iterator$$anon$11.next(Iterator.scala:370)
at scala.collection.Iterator$class.foreach(Iterator.scala:742)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1194)
at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:59)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:104)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:48)
at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:308)
at scala.collection.AbstractIterator.to(Iterator.scala:1194)
at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:300)
at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1194)
at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:287)
at scala.collection.AbstractIterator.toArray(Iterator.scala:1194)
at org.apache.spark.sql.catalyst.trees.TreeNode.transformChildren(TreeNode.scala:305)
at org.apache.spark.sql.catalyst.trees.TreeNode.transformDown(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformDown$1.apply(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformDown$1.apply(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$4.apply(TreeNode.scala:265)
at scala.collection.Iterator$$anon$11.next(Iterator.scala:370)
at scala.collection.Iterator$class.foreach(Iterator.scala:742)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1194)
at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:59)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:104)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:48)
at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:308)
at scala.collection.AbstractIterator.to(Iterator.scala:1194)
at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:300)
at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1194)
at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:287)
at scala.collection.AbstractIterator.toArray(Iterator.scala:1194)
at org.apache.spark.sql.catalyst.trees.TreeNode.transformChildren(TreeNode.scala:305)
at org.apache.spark.sql.catalyst.trees.TreeNode.transformDown(TreeNode.scala:248)
at org.apache.spark.sql.catalyst.plans.QueryPlan.transformExpressionDown$1(QueryPlan.scala:75)
at org.apache.spark.sql.catalyst.plans.QueryPlan.org$apache$spark$sql$catalyst$plans$QueryPlan$$recursiveTransform$1(QueryPlan.scala:85)
at org.apache.spark.sql.catalyst.plans.QueryPlan$$anonfun$org$apache$spark$sql$catalyst$plans$QueryPlan$$recursiveTransform$1$1.apply(QueryPlan.scala:89)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:245)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:245)
at scala.collection.immutable.List.foreach(List.scala:381)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:245)
at scala.collection.immutable.List.map(List.scala:285)
at org.apache.spark.sql.catalyst.plans.QueryPlan.org$apache$spark$sql$catalyst$plans$QueryPlan$$recursiveTransform$1(QueryPlan.scala:89)
at org.apache.spark.sql.catalyst.plans.QueryPlan$$anonfun$1.apply(QueryPlan.scala:93)
at scala.collection.Iterator$$anon$11.next(Iterator.scala:370)
at scala.collection.Iterator$class.foreach(Iterator.scala:742)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1194)
at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:59)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:104)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:48)
at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:308)
at scala.collection.AbstractIterator.to(Iterator.scala:1194)
at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:300)
at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1194)
at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:287)
at scala.collection.AbstractIterator.toArray(Iterator.scala:1194)
at org.apache.spark.sql.catalyst.plans.QueryPlan.transformExpressionsDown(QueryPlan.scala:93)
at org.apache.spark.sql.catalyst.plans.QueryPlan.transformExpressions(QueryPlan.scala:64)
at org.apache.spark.sql.catalyst.plans.QueryPlan$$anonfun$transformAllExpressions$1.applyOrElse(QueryPlan.scala:134)
at org.apache.spark.sql.catalyst.plans.QueryPlan$$anonfun$transformAllExpressions$1.applyOrElse(QueryPlan.scala:133)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$3.apply(TreeNode.scala:243)
at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$3.apply(TreeNode.scala:243)
at org.apache.spark.sql.catalyst.trees.CurrentOrigin$.withOrigin(TreeNode.scala:53)
at org.apache.spark.sql.catalyst.trees.TreeNode.transformDown(TreeNode.scala:242)
at org.apache.spark.sql.catalyst.trees.TreeNode.transform(TreeNode.scala:233)
at org.apache.spark.sql.catalyst.plans.QueryPlan.transformAllExpressions(QueryPlan.scala:133)
at org.apache.spark.sql.catalyst.analysis.ResolveUpCast$.apply(Analyzer.scala:1211)
at org.apache.spark.sql.catalyst.analysis.ResolveUpCast$.apply(Analyzer.scala:1195)
at org.apache.spark.sql.catalyst.rules.RuleExecutor$$anonfun$execute$1$$anonfun$apply$1.apply(RuleExecutor.scala:83)
at org.apache.spark.sql.catalyst.rules.RuleExecutor$$anonfun$execute$1$$anonfun$apply$1.apply(RuleExecutor.scala:80)
at scala.collection.LinearSeqOptimized$class.foldLeft(LinearSeqOptimized.scala:124)
at scala.collection.immutable.List.foldLeft(List.scala:84)
at org.apache.spark.sql.catalyst.rules.RuleExecutor$$anonfun$execute$1.apply(RuleExecutor.scala:80)
at org.apache.spark.sql.catalyst.rules.RuleExecutor$$anonfun$execute$1.apply(RuleExecutor.scala:72)
at scala.collection.immutable.List.foreach(List.scala:381)
at org.apache.spark.sql.catalyst.rules.RuleExecutor.execute(RuleExecutor.scala:72)
at org.apache.spark.sql.catalyst.encoders.ExpressionEncoder.resolve(ExpressionEncoder.scala:253)
at org.apache.spark.sql.Dataset.<init>(Dataset.scala:78)
at org.apache.spark.sql.GroupedDataset.aggUntyped(GroupedDataset.scala:240)
at org.apache.spark.sql.GroupedDataset.agg(GroupedDataset.scala:253)
at ArrayExample$.main(ArrayExample.scala:22)
at ArrayExample.main(ArrayExample.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.apache.spark.deploy.SparkSubmit$.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:731)
at org.apache.spark.deploy.SparkSubmit$.doRunMain$1(SparkSubmit.scala:181)
at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:206)
at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:121)
at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)