[SPARK-24348][SQL] "element_at" error fix

[wajda]

What changes were proposed in this pull request?

Fixes a scala.MatchError in the element_at operation - SPARK-24348

When calling element_at with a wrong first operand type an AnalysisException should be thrown instead of scala.MatchError

Example:

select element_at('foo', 1)

results in:

scala.MatchError: StringType (of class org.apache.spark.sql.types.StringType$)
	at org.apache.spark.sql.catalyst.expressions.ElementAt.inputTypes(collectionOperations.scala:1469)
	at org.apache.spark.sql.catalyst.expressions.ExpectsInputTypes$class.checkInputDataTypes(ExpectsInputTypes.scala:44)
	at org.apache.spark.sql.catalyst.expressions.ElementAt.checkInputDataTypes(collectionOperations.scala:1478)
	at org.apache.spark.sql.catalyst.expressions.Expression.resolved$lzycompute(Expression.scala:168)
	at org.apache.spark.sql.catalyst.expressions.Expression.resolved(Expression.scala:168)
	at org.apache.spark.sql.catalyst.analysis.Analyzer$ResolveAliases$$anonfun$org$apache$spark$sql$catalyst$analysis$Analyzer$ResolveAliases$$assignAliases$1$$anonfun$apply$3.applyOrElse(Analyzer.scala:256)
	at org.apache.spark.sql.catalyst.analysis.Analyzer$ResolveAliases$$anonfun$org$apache$spark$sql$catalyst$analysis$Analyzer$ResolveAliases$$assignAliases$1$$anonfun$apply$3.applyOrElse(Analyzer.scala:252)
	at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformUp$1.apply(TreeNode.scala:289)
	at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformUp$1.apply(TreeNode.scala:289)
	at org.apache.spark.sql.catalyst.trees.CurrentOrigin$.withOrigin(TreeNode.scala:70)
	at org.apache.spark.sql.catalyst.trees.TreeNode.transformUp(TreeNode.scala:288)

How was this patch tested?

unit tests

[kiszk]

cc @ueshin

[ueshin]

Good catch!
I guess we should check other functions while we are here. I found ArrayPosition has similar problem for now. Could you fix it as well?

[ueshin]

ok to test.

[wajda]

Yep, just have fixed that one as well :)
#21401

[maropu]

Please check the error message, too.

[SparkQA]

Test build #90974 has finished for PR 21395 at commit ec2e4a6.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[gatorsmile]

LGTM

Thanks, Merged to master!

[gatorsmile]

BTW, normally, we prefer to

  override def inputTypes: Seq[AbstractDataType] = {
    val rightInputType = left.dataType match {
      case _: ArrayType => IntegerType
      case _: MapType => left.dataType.asInstanceOf[MapType].keyType
      case _ => AnyDataType // no match for a wrong 'left' expression type
    }
    Seq(TypeCollection(ArrayType, MapType), rightInputType)
  }

[SparkQA]

Test build #90986 has finished for PR 21395 at commit 045307b.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.