From 82d316b419f5ae872250c6732d2ee2df19eca93f Mon Sep 17 00:00:00 2001
From: Gabriel <gabrielleebuaa@gmail.com>
Date: Sat, 24 Dec 2022 21:57:46 +0800
Subject: [PATCH] [bug](decimalv3) Fix wrong decimal scale for arithmetic expr
 (#15316)

---
 .../org/apache/doris/analysis/ArithmeticExpr.java | 15 ++++++++++-----
 .../decimalv3/test_arithmetic_expressions.out     | 15 +++++++++++++++
 .../decimalv3/test_arithmetic_expressions.groovy  |  3 +++
 3 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/fe/fe-core/src/main/java/org/apache/doris/analysis/ArithmeticExpr.java b/fe/fe-core/src/main/java/org/apache/doris/analysis/ArithmeticExpr.java
index 67b5359348..e5502fe635 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/analysis/ArithmeticExpr.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/analysis/ArithmeticExpr.java
@@ -533,14 +533,14 @@ public class ArithmeticExpr extends Expr {
                     scale = Math.max(t1Scale, t2Scale);
                     precision = Math.max(widthOfIntPart1, widthOfIntPart2) + scale;
                 }
-                if (precision < scale) {
-                    type = castBinaryOp(Type.DOUBLE);
-                    break;
-                }
                 if (precision > ScalarType.MAX_DECIMAL128_PRECISION) {
                     // TODO(gabriel): if precision is bigger than 38?
                     precision = ScalarType.MAX_DECIMAL128_PRECISION;
                 }
+                if (precision < scale) {
+                    type = castBinaryOp(Type.DOUBLE);
+                    break;
+                }
                 type = ScalarType.createDecimalV3Type(precision, scale);
                 if (op == Operator.ADD || op == Operator.SUBTRACT) {
                     if (!Type.matchExactType(type, children.get(0).type)) {
@@ -550,7 +550,12 @@ public class ArithmeticExpr extends Expr {
                         castChild(type, 1);
                     }
                 } else if (op == Operator.DIVIDE && (t2Scale != 0) && t1.isDecimalV3()) {
-                    castChild(ScalarType.createDecimalV3Type(precision, t1Scale + t2Scale), 0);
+                    int targetScale = t1Scale + t2Scale;
+                    if (precision < targetScale) {
+                        type = castBinaryOp(Type.DOUBLE);
+                        break;
+                    }
+                    castChild(ScalarType.createDecimalV3Type(precision, targetScale), 0);
                 }
                 break;
             case INT_DIVIDE:
diff --git a/regression-test/data/datatype_p0/decimalv3/test_arithmetic_expressions.out b/regression-test/data/datatype_p0/decimalv3/test_arithmetic_expressions.out
index a8d9df8d8d..4f68777f2a 100644
--- a/regression-test/data/datatype_p0/decimalv3/test_arithmetic_expressions.out
+++ b/regression-test/data/datatype_p0/decimalv3/test_arithmetic_expressions.out
@@ -17,3 +17,18 @@
 1.440000000000000000000000000000000000
 1.800000000000000000000000000000000000
 
+-- !select --
+1.7160000000000002
+1.8719999999999999
+2.34
+
+-- !select --
+2.9446560000000006
+3.504384
+5.4756
+
+-- !select --
+1.7424
+2.0736
+3.2399999999999998
+
diff --git a/regression-test/suites/datatype_p0/decimalv3/test_arithmetic_expressions.groovy b/regression-test/suites/datatype_p0/decimalv3/test_arithmetic_expressions.groovy
index 44cd313fa0..301d719b15 100644
--- a/regression-test/suites/datatype_p0/decimalv3/test_arithmetic_expressions.groovy
+++ b/regression-test/suites/datatype_p0/decimalv3/test_arithmetic_expressions.groovy
@@ -45,5 +45,8 @@ suite("test_arithmetic_expressions") {
     qt_select "select k1 * k2 from ${table1} order by k1"
     qt_select "select * from (select k1 * k2 from ${table1} union all select k3 from ${table1}) a order by 1"
 
+    qt_select "select k1 * k2 * k3 from ${table1} order by k1"
+    qt_select "select k1 * k2 * k3 * k1 * k2 * k3 from ${table1} order by k1"
+    qt_select "select k1 * k2 / k3 * k1 * k2 * k3 from ${table1} order by k1"
     sql "drop table if exists ${table1}"
 }