diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/math.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/math.scala index 7e7a0e280a62d..efb7dc50fd8b1 100644 --- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/math.scala +++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/math.scala @@ -555,7 +555,9 @@ case class Round(child: Expression, scale: Expression) override def foldable: Boolean = child.foldable override lazy val dataType: DataType = child.dataType match { - case DecimalType.Fixed(p, s) => DecimalType(p, _scale) + // if the new scale is bigger which means we are scaling up, + // keep the original scale as `Decimal` does + case DecimalType.Fixed(p, s) => DecimalType(p, if (_scale > s) s else _scale) case t => t } diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/types/decimal/DecimalSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/types/decimal/DecimalSuite.scala index 5f312964e5bf7..9e8cd026d2a32 100644 --- a/sql/catalyst/src/test/scala/org/apache/spark/sql/types/decimal/DecimalSuite.scala +++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/types/decimal/DecimalSuite.scala @@ -24,14 +24,14 @@ import org.scalatest.PrivateMethodTester import scala.language.postfixOps class DecimalSuite extends SparkFunSuite with PrivateMethodTester { - test("creating decimals") { - /** Check that a Decimal has the given string representation, precision and scale */ - def checkDecimal(d: Decimal, string: String, precision: Int, scale: Int): Unit = { - assert(d.toString === string) - assert(d.precision === precision) - assert(d.scale === scale) - } + /** Check that a Decimal has the given string representation, precision and scale */ + private def checkDecimal(d: Decimal, string: String, precision: Int, scale: Int): Unit = { + assert(d.toString === string) + assert(d.precision === precision) + assert(d.scale === scale) + } + test("creating decimals") { checkDecimal(new Decimal(), "0", 1, 0) checkDecimal(Decimal(BigDecimal("10.030")), "10.030", 5, 3) checkDecimal(Decimal(BigDecimal("10.030"), 4, 1), "10.0", 4, 1) @@ -53,6 +53,15 @@ class DecimalSuite extends SparkFunSuite with PrivateMethodTester { intercept[IllegalArgumentException](Decimal(1e17.toLong, 17, 0)) } + test("creating decimals with negative scale") { + checkDecimal(Decimal(BigDecimal("98765"), 5, -3), "9.9E+4", 5, -3) + checkDecimal(Decimal(BigDecimal("314.159"), 6, -2), "3E+2", 6, -2) + checkDecimal(Decimal(BigDecimal(1.579e12), 4, -9), "1.579E+12", 4, -9) + checkDecimal(Decimal(BigDecimal(1.579e12), 4, -10), "1.58E+12", 4, -10) + checkDecimal(Decimal(103050709L, 9, -10), "1.03050709E+18", 9, -10) + checkDecimal(Decimal(1e8.toLong, 10, -10), "1.00000000E+18", 10, -10) + } + test("double and long values") { /** Check that a Decimal converts to the given double and long values */ def checkValues(d: Decimal, doubleValue: Double, longValue: Long): Unit = {