[fix](nereids) fix wrong result precision for add/sub

jacktengg · Oct 26, 2023 · 7b3f76f · 7b3f76f
1 parent 2229d82
commit 7b3f76f
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Showing 3 changed files with 8 additions and 4 deletions.
diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/Add.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/Add.java
@@ -49,7 +49,9 @@ public Expression withChildren(List<Expression> children) {
 
     @Override
     public DecimalV3Type getDataTypeForDecimalV3(DecimalV3Type t1, DecimalV3Type t2) {
-        return (DecimalV3Type) DecimalV3Type.widerDecimalV3Type(t1, t2, false);
+        DecimalV3Type decimalV3Type = (DecimalV3Type) DecimalV3Type.widerDecimalV3Type(t1, t2, false);
+        return (DecimalV3Type) DecimalV3Type.createDecimalV3Type(decimalV3Type.getPrecision() + 1,
+                decimalV3Type.getScale());
     }
 
     @Override

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/Subtract.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/Subtract.java
@@ -49,7 +49,9 @@ public Expression withChildren(List<Expression> children) {
 
     @Override
     public DecimalV3Type getDataTypeForDecimalV3(DecimalV3Type t1, DecimalV3Type t2) {
-        return (DecimalV3Type) DecimalV3Type.widerDecimalV3Type(t1, t2, false);
+        DecimalV3Type decimalV3Type = (DecimalV3Type) DecimalV3Type.widerDecimalV3Type(t1, t2, false);
+        return (DecimalV3Type) DecimalV3Type.createDecimalV3Type(decimalV3Type.getPrecision() + 1,
+                decimalV3Type.getScale());
     }
 
     @Override

diff --git a/fe/fe-core/src/test/java/org/apache/doris/nereids/util/TypeCoercionUtilsTest.java b/fe/fe-core/src/test/java/org/apache/doris/nereids/util/TypeCoercionUtilsTest.java
@@ -727,12 +727,12 @@ public void testDecimalArithmetic() {
                 new DecimalV3Literal(new BigDecimal("123.45")));
         expression = TypeCoercionUtils.processBinaryArithmetic(add);
         Assertions.assertEquals(expression.child(0),
-                new Cast(multiply.child(0), DecimalV3Type.createDecimalV3Type(9, 3)));
+                new Cast(multiply.child(0), DecimalV3Type.createDecimalV3Type(10, 3)));
 
         Subtract sub = new Subtract(new DecimalLiteral(new BigDecimal("987654.321")),
                 new DecimalV3Literal(new BigDecimal("123.45")));
         expression = TypeCoercionUtils.processBinaryArithmetic(sub);
         Assertions.assertEquals(expression.child(0),
-                new Cast(multiply.child(0), DecimalV3Type.createDecimalV3Type(9, 3)));
+                new Cast(multiply.child(0), DecimalV3Type.createDecimalV3Type(10, 3)));
     }
 }