[SPARK-2658][SQL] Add rule for true = 1.

Author: Michael Armbrust <michael@databricks.com>

Closes #1556 from marmbrus/fixBooleanEqualsOne and squashes the following commits:

ad8edd4 [Michael Armbrust] Add rule for true = 1 and false = 0.

3 files changed, 24 insertions, 1 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/HiveTypeCoercion.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/HiveTypeCoercion.scala
index 76ddeba9cb..9887856b9c 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/HiveTypeCoercion.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/HiveTypeCoercion.scala
@@ -231,10 +231,20 @@ trait HiveTypeCoercion {
    * Changes Boolean values to Bytes so that expressions like true < false can be Evaluated.
    */
   object BooleanComparisons extends Rule[LogicalPlan] {
+    val trueValues = Seq(1, 1L, 1.toByte, 1.toShort, BigDecimal(1)).map(Literal(_))
+    val falseValues = Seq(0, 0L, 0.toByte, 0.toShort, BigDecimal(0)).map(Literal(_))
+
     def apply(plan: LogicalPlan): LogicalPlan = plan transformAllExpressions {
       // Skip nodes who's children have not been resolved yet.
       case e if !e.childrenResolved => e
-      // No need to change EqualTo operators as that actually makes sense for boolean types.
+
+      // Hive treats (true = 1) as true and (false = 0) as true.
+      case EqualTo(l @ BooleanType(), r) if trueValues.contains(r) => l
+      case EqualTo(l, r @ BooleanType()) if trueValues.contains(l) => r
+      case EqualTo(l @ BooleanType(), r) if falseValues.contains(r) => Not(l)
+      case EqualTo(l, r @ BooleanType()) if falseValues.contains(l) => Not(r)
+
+      // No need to change other EqualTo operators as that actually makes sense for boolean types.
       case e: EqualTo => e
       // Otherwise turn them to Byte types so that there exists and ordering.
       case p: BinaryComparison
diff --git a/sql/hive/src/test/resources/golden/boolean = number-0-6b6975fa1892cc48edd87dc0df48a7c0 b/sql/hive/src/test/resources/golden/boolean = number-0-6b6975fa1892cc48edd87dc0df48a7c0
new file mode 100644
index 0000000000..4d1ebdcde2
--- /dev/null
+++ b/sql/hive/src/test/resources/golden/boolean = number-0-6b6975fa1892cc48edd87dc0df48a7c0
@@ -0,0 +1 @@
+true	true	true	true	true	true	false	false	false	false	false	false	false	false	false	false	false	false	true	true	true	true	true	true	false	false	false	false	false	false	false	false	false	false	false	false
diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveQuerySuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveQuerySuite.scala
index eb7df71728..6f36a4f8cb 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveQuerySuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveQuerySuite.scala
@@ -30,6 +30,18 @@ case class TestData(a: Int, b: String)
  */
 class HiveQuerySuite extends HiveComparisonTest {
 
+  createQueryTest("boolean = number",
+    """
+      |SELECT
+      |  1 = true, 1L = true, 1Y = true, true = 1, true = 1L, true = 1Y,
+      |  0 = true, 0L = true, 0Y = true, true = 0, true = 0L, true = 0Y,
+      |  1 = false, 1L = false, 1Y = false, false = 1, false = 1L, false = 1Y,
+      |  0 = false, 0L = false, 0Y = false, false = 0, false = 0L, false = 0Y,
+      |  2 = true, 2L = true, 2Y = true, true = 2, true = 2L, true = 2Y,
+      |  2 = false, 2L = false, 2Y = false, false = 2, false = 2L, false = 2Y
+      |FROM src LIMIT 1
+    """.stripMargin)
+
   test("CREATE TABLE AS runs once") {
     hql("CREATE TABLE foo AS SELECT 1 FROM src LIMIT 1").collect()
     assert(hql("SELECT COUNT(*) FROM foo").collect().head.getLong(0) === 1,