add equal type constraint to EqualTo

Author: cloud-fan

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/predicates.scala

@@ -178,10 +178,12 @@ abstract class BinaryComparison extends BinaryExpression with Predicate {
         s"differing types in ${this.getClass.getSimpleName} " +
         s"(${left.dataType} and ${right.dataType}).")
     } else {
-      TypeUtils.checkForOrderingExpr(left.dataType, "operator " + symbol)
+      checkTypesInternal(dataType)
     }
   }
 
+  protected def checkTypesInternal(t: DataType): TypeCheckResult
+
   override def eval(input: Row): Any = {
     val evalE1 = left.eval(input)
     if (evalE1 == null) {
@@ -203,8 +205,7 @@ abstract class BinaryComparison extends BinaryExpression with Predicate {
 case class EqualTo(left: Expression, right: Expression) extends BinaryComparison {
   override def symbol: String = "="
 
-  // EqualTo don't need 2 equal orderable types
-  override def checkInputDataTypes(): TypeCheckResult = TypeCheckResult.success
+  override protected def checkTypesInternal(t: DataType) = TypeCheckResult.success
 
   protected override def evalInternal(l: Any, r: Any) = {
     if (left.dataType != BinaryType) l == r
@@ -216,8 +217,7 @@ case class EqualNullSafe(left: Expression, right: Expression) extends BinaryComp
   override def symbol: String = "<=>"
   override def nullable: Boolean = false
 
-  // EqualNullSafe don't need 2 equal orderable types
-  override def checkInputDataTypes(): TypeCheckResult = TypeCheckResult.success
+  override protected def checkTypesInternal(t: DataType) = TypeCheckResult.success
 
   override def eval(input: Row): Any = {
     val l = left.eval(input)
@@ -235,6 +235,9 @@ case class EqualNullSafe(left: Expression, right: Expression) extends BinaryComp
 case class LessThan(left: Expression, right: Expression) extends BinaryComparison {
   override def symbol: String = "<"
 
+  override protected def checkTypesInternal(t: DataType) =
+    TypeUtils.checkForOrderingExpr(left.dataType, "operator " + symbol)
+
   private lazy val ordering = TypeUtils.getOrdering(left.dataType)
 
   protected override def evalInternal(evalE1: Any, evalE2: Any) = ordering.lt(evalE1, evalE2)
@@ -243,6 +246,9 @@ case class LessThan(left: Expression, right: Expression) extends BinaryCompariso
 case class LessThanOrEqual(left: Expression, right: Expression) extends BinaryComparison {
   override def symbol: String = "<="
 
+  override protected def checkTypesInternal(t: DataType) =
+    TypeUtils.checkForOrderingExpr(left.dataType, "operator " + symbol)
+
   private lazy val ordering = TypeUtils.getOrdering(left.dataType)
 
   protected override def evalInternal(evalE1: Any, evalE2: Any) = ordering.lteq(evalE1, evalE2)
@@ -251,6 +257,9 @@ case class LessThanOrEqual(left: Expression, right: Expression) extends BinaryCo
 case class GreaterThan(left: Expression, right: Expression) extends BinaryComparison {
   override def symbol: String = ">"
 
+  override protected def checkTypesInternal(t: DataType) =
+    TypeUtils.checkForOrderingExpr(left.dataType, "operator " + symbol)
+
   private lazy val ordering = TypeUtils.getOrdering(left.dataType)
 
   protected override def evalInternal(evalE1: Any, evalE2: Any) = ordering.gt(evalE1, evalE2)
@@ -259,6 +268,9 @@ case class GreaterThan(left: Expression, right: Expression) extends BinaryCompar
 case class GreaterThanOrEqual(left: Expression, right: Expression) extends BinaryComparison {
   override def symbol: String = ">="
 
+  override protected def checkTypesInternal(t: DataType) =
+    TypeUtils.checkForOrderingExpr(left.dataType, "operator " + symbol)
+
   private lazy val ordering = TypeUtils.getOrdering(left.dataType)
 
   protected override def evalInternal(evalE1: Any, evalE2: Any) = ordering.gteq(evalE1, evalE2)

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/ExpressionTypeCheckingSuite.scala

@@ -96,16 +96,16 @@ class ExpressionTypeCheckingSuite extends FunSuite {
   }
 
   test("check types for predicates") {
-    // EqualTo don't have type constraint
-    assertSuccess(EqualTo('intField, 'booleanField))
-    assertSuccess(EqualNullSafe('intField, 'booleanField))
-
     // We will cast String to Double for binary comparison
+    assertSuccess(EqualTo('intField, 'stringField))
+    assertSuccess(EqualNullSafe('intField, 'stringField))
     assertSuccess(LessThan('intField, 'stringField))
     assertSuccess(LessThanOrEqual('intField, 'stringField))
     assertSuccess(GreaterThan('intField, 'stringField))
     assertSuccess(GreaterThanOrEqual('intField, 'stringField))
 
+    assertErrorForDifferingTypes(EqualTo('intField, 'booleanField))
+    assertErrorForDifferingTypes(EqualNullSafe('intField, 'booleanField))
     assertErrorForDifferingTypes(LessThan('intField, 'booleanField))
     assertErrorForDifferingTypes(LessThanOrEqual('intField, 'booleanField))
     assertErrorForDifferingTypes(GreaterThan('intField, 'booleanField))