[SPARK-10245] [SQL] Fix decimal literals with precision < scale

In BigDecimal or java.math.BigDecimal, the precision could be smaller than scale, for example, BigDecimal("0.001") has precision = 1 and scale = 3. But DecimalType require that the precision should be larger than scale, so we should use the maximum of precision and scale when inferring the schema from decimal literal.

Author: Davies Liu <davies@databricks.com>

Closes #8428 from davies/smaller_decimal.

1 files changed, 10 insertions, 0 deletions

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
index dcb4e83710..aa07665c6b 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
@@ -1627,6 +1627,16 @@ class SQLQuerySuite extends QueryTest with SharedSQLContext {
       Row(null))
   }
 
+  test("precision smaller than scale") {
+    checkAnswer(sql("select 10.00"), Row(BigDecimal("10.00")))
+    checkAnswer(sql("select 1.00"), Row(BigDecimal("1.00")))
+    checkAnswer(sql("select 0.10"), Row(BigDecimal("0.10")))
+    checkAnswer(sql("select 0.01"), Row(BigDecimal("0.01")))
+    checkAnswer(sql("select 0.001"), Row(BigDecimal("0.001")))
+    checkAnswer(sql("select -0.01"), Row(BigDecimal("-0.01")))
+    checkAnswer(sql("select -0.001"), Row(BigDecimal("-0.001")))
+  }
+
   test("external sorting updates peak execution memory") {
     withSQLConf((SQLConf.EXTERNAL_SORT.key, "true")) {
       val sc = sqlContext.sparkContext