title: Is Spark DataFrame nested structure limited for selection?
body: <p>I have a json file with some data, I’m able to create DataFrame out of it and the schema for particular part of it I’m interested in looks like following:</p>
  
  <p><code>val json: DataFrame = sqlc.load("entities_with_address2.json", "json")</code></p>
  
  <pre><code>root
   |-- attributes: struct (nullable = true)
   |    |-- Address2: array (nullable = true)
   |    |    |-- value: struct (nullable = true)
   |    |    |    |-- Zip: array (nullable = true)
   |    |    |    |    |-- element: struct (containsNull = true)
   |    |    |    |    |    |-- value: struct (nullable = true)
   |    |    |    |    |    |    |-- Zip5: array (nullable = true)
   |    |    |    |    |    |    |    |-- element: struct (containsNull = true)
   |    |    |    |    |    |    |    |    |-- value: string (nullable = true)
  </code></pre>
  
  <p>When I’m trying to just select the deepest field:
  <code>json.select("attributes.Address2.value.Zip.value.Zip5").collect()</code></p>
  
  <p>It gives me an exception: 
  <code>org.apache.spark.sql.AnalysisException: GetField is not valid on fields of type ArrayType(ArrayType(StructType(StructField(value, StructType(StructField(Zip5, ArrayType(StructType(StructField(value, StringType, true)), true), true)), true)), true), true);</code></p>
  
  <p>By looking at the resolveGetField method of LogicalPlan I see that it's possible to select from StructType or from ArrayType(StructType), but is there any way to select deeper? How can I select field I need?</p>
  
  <p>Here is the full exception.</p>
  
  <pre><code>    org.apache.spark.sql.AnalysisException: GetField is not valid on fields of type ArrayType(ArrayType(StructType(StructField(value,StructType(StructField(Zip5,ArrayType(StructType(StructField(value,StringType,true)),true),true)),true)),true),true);
          at org.apache.spark.sql.catalyst.plans.logical.LogicalPlan.resolveGetField(LogicalPlan.scala:265)
          at org.apache.spark.sql.catalyst.plans.logical.LogicalPlan$$anonfun$3.apply(LogicalPlan.scala:214)
          at org.apache.spark.sql.catalyst.plans.logical.LogicalPlan$$anonfun$3.apply(LogicalPlan.scala:214)
          at scala.collection.LinearSeqOptimized$class.foldLeft(LinearSeqOptimized.scala:111)
          at scala.collection.immutable.List.foldLeft(List.scala:84)
          at org.apache.spark.sql.catalyst.plans.logical.LogicalPlan.resolve(LogicalPlan.scala:214)
          at org.apache.spark.sql.catalyst.plans.logical.LogicalPlan.resolveChildren(LogicalPlan.scala:117)
          at org.apache.spark.sql.catalyst.analysis.CheckAnalysis$$anonfun$checkAnalysis$1$$anonfun$apply$1.applyOrElse(CheckAnalysis.scala:50)
          at org.apache.spark.sql.catalyst.analysis.CheckAnalysis$$anonfun$checkAnalysis$1$$anonfun$apply$1.applyOrElse(CheckAnalysis.scala:46)
          at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformUp$1.apply(TreeNode.scala:252)
          at org.apache.spark.sql.catalyst.trees.TreeNode$$anonfun$transformUp$1.apply(TreeNode.scala:252)
          at org.apache.spark.sql.catalyst.trees.CurrentOrigin$.withOrigin(TreeNode.scala:51)
          at org.apache.spark.sql.catalyst.trees.TreeNode.transformUp(TreeNode.scala:251)
          at org.apache.spark.sql.catalyst.plans.QueryPlan.org$apache$spark$sql$catalyst$plans$QueryPlan$$transformExpressionUp$1(QueryPlan.scala:108)
          at org.apache.spark.sql.catalyst.plans.QueryPlan$$anonfun$2$$anonfun$apply$2.apply(QueryPlan.scala:123)
          at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
          at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
          at scala.collection.immutable.List.foreach(List.scala:318)
          at scala.collection.TraversableLike$class.map(TraversableLike.scala:244)
          at scala.collection.AbstractTraversable.map(Traversable.scala:105)
          at org.apache.spark.sql.catalyst.plans.QueryPlan$$anonfun$2.apply(QueryPlan.scala:122)
          at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)
          at scala.collection.Iterator$class.foreach(Iterator.scala:727)
          at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
          at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:48)
          at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:103)
          at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:47)
          at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:273)
          at scala.collection.AbstractIterator.to(Iterator.scala:1157)
          at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:265)
          at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1157)
          at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:252)
          at scala.collection.AbstractIterator.toArray(Iterator.scala:1157)
          at org.apache.spark.sql.catalyst.plans.QueryPlan.transformExpressionsUp(QueryPlan.scala:127)
          at org.apache.spark.sql.catalyst.analysis.CheckAnalysis$$anonfun$checkAnalysis$1.apply(CheckAnalysis.scala:46)
          at org.apache.spark.sql.catalyst.analysis.CheckAnalysis$$anonfun$checkAnalysis$1.apply(CheckAnalysis.scala:44)
          at org.apache.spark.sql.catalyst.trees.TreeNode.foreachUp(TreeNode.scala:89)
          at org.apache.spark.sql.catalyst.analysis.CheckAnalysis$class.checkAnalysis(CheckAnalysis.scala:44)
          at org.apache.spark.sql.catalyst.analysis.Analyzer.checkAnalysis(Analyzer.scala:40)
          at org.apache.spark.sql.SQLContext$QueryExecution.assertAnalyzed(SQLContext.scala:1080)
          at org.apache.spark.sql.DataFrame.&lt;init&gt;(DataFrame.scala:133)
          at org.apache.spark.sql.DataFrame.logicalPlanToDataFrame(DataFrame.scala:157)
          at org.apache.spark.sql.DataFrame.select(DataFrame.scala:476)
          at org.apache.spark.sql.DataFrame.select(DataFrame.scala:491)
          at com.reltio.analytics.PREDF.test(PREDF.scala:55)
          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
          at java.lang.reflect.Method.invoke(Method.java:606)
          at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
          at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
          at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
          at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
          at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
          at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
          at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
          at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
          at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
          at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
          at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
          at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
          at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
          at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
          at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
          at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:211)
          at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:67)
  </code></pre>