[SPARK-5462] [SQL] Use analyzed query plan in DataFrame.apply()

This patch changes DataFrame's `apply()` method to use an analyzed query plan when resolving column names.  This fixes a bug where `apply` would throw "invalid call to qualifiers on unresolved object" errors when called on DataFrames constructed via `SQLContext.sql()`.

Author: Josh Rosen <joshrosen@databricks.com>

Closes #4282 from JoshRosen/SPARK-5462 and squashes the following commits:

b9e6da2 [Josh Rosen] [SPARK-5462] Use analyzed query plan in DataFrame.apply().

sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala

@@ -111,14 +111,16 @@ class DataFrame protected[sql](
   /** Returns the list of numeric columns, useful for doing aggregation. */
   protected[sql] def numericColumns: Seq[Expression] = {
     schema.fields.filter(_.dataType.isInstanceOf[NumericType]).map { n =>
-      logicalPlan.resolve(n.name, sqlContext.analyzer.resolver).get
+      queryExecution.analyzed.resolve(n.name, sqlContext.analyzer.resolver).get
     }
   }
 
   /** Resolves a column name into a Catalyst [[NamedExpression]]. */
   protected[sql] def resolve(colName: String): NamedExpression = {
-    logicalPlan.resolve(colName, sqlContext.analyzer.resolver).getOrElse(throw new RuntimeException(
-      s"""Cannot resolve column name "$colName" among (${schema.fieldNames.mkString(", ")})"""))
+    queryExecution.analyzed.resolve(colName, sqlContext.analyzer.resolver).getOrElse {
+      throw new RuntimeException(
+        s"""Cannot resolve column name "$colName" among (${schema.fieldNames.mkString(", ")})""")
+    }
   }
 
   /** Left here for compatibility reasons. */

sql/core/src/test/scala/org/apache/spark/sql/DataFrameSuite.scala

@@ -276,5 +276,9 @@ class DataFrameSuite extends QueryTest {
     )
   }
 
+  test("apply on query results (SPARK-5462)") {
+    val df = testData.sqlContext.sql("select key from testData")
+    checkAnswer(df("key"), testData.select('key).collect().toSeq)
+  }
 
 }