[SPARK-4536][SQL] Add sqrt and abs to Spark SQL DSL

Spark SQL has embeded sqrt and abs but DSL doesn't support those functions.

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>

Closes #3401 from sarutak/dsl-missing-operator and squashes the following commits:

07700cf [Kousuke Saruta] Modified Literal(null, NullType) to Literal(null) in DslQuerySuite
8f366f8 [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into dsl-missing-operator
1b88e2e [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into dsl-missing-operator
0396f89 [Kousuke Saruta] Added sqrt and abs to Spark SQL DSL

2 files changed, 72 insertions, 0 deletions

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/DslQuerySuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/DslQuerySuite.scala
index 94bd97758f..1a330a2bb6 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/DslQuerySuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/DslQuerySuite.scala
@@ -282,4 +282,72 @@ class DslQuerySuite extends QueryTest {
       (1, "1", "11") :: (2, "2", "22") :: (3, "3", "33") :: Nil
     )
   }
+
+  test("sqrt") {
+    checkAnswer(
+      testData.select(sqrt('key)).orderBy('key asc),
+      (1 to 100).map(n => Seq(math.sqrt(n)))
+    )
+
+    checkAnswer(
+      testData.select(sqrt('value), 'key).orderBy('key asc, 'value asc),
+      (1 to 100).map(n => Seq(math.sqrt(n), n))
+    )
+
+    checkAnswer(
+      testData.select(sqrt(Literal(null))),
+      (1 to 100).map(_ => Seq(null))
+    )
+  }
+
+  test("abs") {
+    checkAnswer(
+      testData.select(abs('key)).orderBy('key asc),
+      (1 to 100).map(n => Seq(n))
+    )
+
+    checkAnswer(
+      negativeData.select(abs('key)).orderBy('key desc),
+      (1 to 100).map(n => Seq(n))
+    )
+
+    checkAnswer(
+      testData.select(abs(Literal(null))),
+      (1 to 100).map(_ => Seq(null))
+    )
+  }
+
+  test("upper") {
+    checkAnswer(
+      lowerCaseData.select(upper('l)),
+      ('a' to 'd').map(c => Seq(c.toString.toUpperCase()))
+    )
+
+    checkAnswer(
+      testData.select(upper('value), 'key),
+      (1 to 100).map(n => Seq(n.toString, n))
+    )
+
+    checkAnswer(
+      testData.select(upper(Literal(null))),
+      (1 to 100).map(n => Seq(null))
+    )
+  }
+
+  test("lower") {
+    checkAnswer(
+      upperCaseData.select(lower('L)),
+      ('A' to 'F').map(c => Seq(c.toString.toLowerCase()))
+    )
+
+    checkAnswer(
+      testData.select(lower('value), 'key),
+      (1 to 100).map(n => Seq(n.toString, n))
+    )
+
+    checkAnswer(
+      testData.select(lower(Literal(null))),
+      (1 to 100).map(n => Seq(null))
+    )
+  }
 }
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/TestData.scala b/sql/core/src/test/scala/org/apache/spark/sql/TestData.scala
index 933e027436..bb553a0a1e 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/TestData.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/TestData.scala
@@ -32,6 +32,10 @@ object TestData {
     (1 to 100).map(i => TestData(i, i.toString))).toSchemaRDD
   testData.registerTempTable("testData")
 
+  val negativeData = TestSQLContext.sparkContext.parallelize(
+    (1 to 100).map(i => TestData(-i, (-i).toString))).toSchemaRDD
+  negativeData.registerTempTable("negativeData")
+
   case class LargeAndSmallInts(a: Int, b: Int)
   val largeAndSmallInts =
     TestSQLContext.sparkContext.parallelize(