[ 
https://issues.apache.org/jira/browse/DRILL-7615?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17049861#comment-17049861
 ] 

ASF GitHub Bot commented on DRILL-7615:
---------------------------------------

paul-rogers commented on pull request #2006: DRILL-7615: UNION ALL query 
returns the wrong result for the decimal value
URL: https://github.com/apache/drill/pull/2006#discussion_r386776641
 
 

 ##########
 File path: common/src/main/java/org/apache/drill/common/types/Types.java
 ##########
 @@ -795,15 +807,25 @@ public static boolean isSortable(MinorType type) {
    */
   public static MajorType.Builder calculateTypePrecisionAndScale(MajorType 
leftType, MajorType rightType, MajorType.Builder typeBuilder) {
     if (leftType.getMinorType().equals(rightType.getMinorType())) {
-      final boolean isScalarString = Types.isScalarStringType(leftType) && 
Types.isScalarStringType(rightType);
-      final boolean isDecimal = isDecimalType(leftType);
+      boolean isScalarString = Types.isScalarStringType(leftType) && 
Types.isScalarStringType(rightType);
+      boolean isDecimal = isDecimalType(leftType);
 
-      if ((isScalarString || isDecimal) && leftType.hasPrecision() && 
rightType.hasPrecision()) {
+      if (isScalarString && leftType.hasPrecision() && 
rightType.hasPrecision()) {
         typeBuilder.setPrecision(Math.max(leftType.getPrecision(), 
rightType.getPrecision()));
       }
 
-      if (isDecimal && leftType.hasScale() && rightType.hasScale()) {
-        typeBuilder.setScale(Math.max(leftType.getScale(), 
rightType.getScale()));
+      if (isDecimal) {
+        int scale = Math.max(leftType.getScale(), rightType.getScale());
+        // resulting precision should take into account resulting scale value 
and be calculated as
+        // sum of two components:
+        // - max integer digits number (precision - scale) for left and right;
+        // - resulting scale.
+        // So for the case of cast(9999 as decimal(4,0)) and cast(1.23 as 
decimal(3,2))
+        // resulting scale would be Max(0, 2) = 2 and resulting precision 
would be Max(4 - 0, 3 - 2) + 2 = 6.
+        // In this case, both values would fit into decimal(6, 2): 9999.00, 
1.23
+        int precision = Math.max(leftType.getPrecision() - 
leftType.getScale(), rightType.getPrecision() - rightType.getScale()) + scale;
+        typeBuilder.setPrecision(precision);
+        typeBuilder.setScale(scale);
 
 Review comment:
   Nit: please split the long lint.
   
 
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
[email protected]


> UNION ALL query returns the wrong result for the decimal value
> --------------------------------------------------------------
>
>                 Key: DRILL-7615
>                 URL: https://issues.apache.org/jira/browse/DRILL-7615
>             Project: Apache Drill
>          Issue Type: Bug
>    Affects Versions: 1.14.0
>            Reporter: Vova Vysotskyi
>            Assignee: Vova Vysotskyi
>            Priority: Major
>              Labels: ready-to-commit
>             Fix For: 1.18.0
>
>
> The following query:
> {code:java}
> select cast(1000 as decimal(10,1)) 
> union all 
> select 596.000 
> {code}
> returns incorrect result:
> {code:java}
> 10.000
> 596.000
> {code}
> The expected result is 1000.000 for the first record.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to