From 0423c3767417ecb699274662b9cbc59253f50252 Mon Sep 17 00:00:00 2001
From: 924060929 <lanhuajian@selectdb.com>
Date: Wed, 11 Dec 2024 22:57:51 +0800
Subject: [PATCH] fix

---
 .../trees/plans/logical/LogicalUnion.java     | 32 +++++++++++++++----
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/logical/LogicalUnion.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/logical/LogicalUnion.java
index 7f8ec7a31ff284e..f42f49154c3c5a7 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/logical/LogicalUnion.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/logical/LogicalUnion.java
@@ -297,7 +297,15 @@ public void computeFd(DataTrait.Builder builder) {
     public static Pair<List<List<NamedExpression>>, List<Boolean>> castCommonDataTypeAndNullableByConstants(
             List<List<NamedExpression>> constantExprsList) {
         int columnCount = constantExprsList.isEmpty() ? 0 : constantExprsList.get(0).size();
+        Pair<List<DataType>, List<Boolean>> commonInfo
+                = computeCommonDataTypeAndNullable(constantExprsList, columnCount);
+        List<List<NamedExpression>> castedRows = castToCommonType(constantExprsList, commonInfo.key(), columnCount);
+        List<Boolean> nullables = commonInfo.second;
+        return Pair.of(castedRows, nullables);
+    }
 
+    private static Pair<List<DataType>, List<Boolean>> computeCommonDataTypeAndNullable(
+            List<List<NamedExpression>> constantExprsList, int columnCount) {
         List<Boolean> nullables = Lists.newArrayList();
         List<DataType> commonDataTypes = Lists.newArrayListWithCapacity(columnCount);
         for (int columnId = 0; columnId < columnCount; columnId++) {
@@ -312,19 +320,29 @@ public static Pair<List<List<NamedExpression>>, List<Boolean>> castCommonDataTyp
             nullables.add(nullable);
             commonDataTypes.add(commonDataType);
         }
+        return Pair.of(commonDataTypes, nullables);
+    }
 
+    private static List<List<NamedExpression>> castToCommonType(
+            List<List<NamedExpression>> rows, List<DataType> commonDataTypes, int columnCount) {
         ImmutableList.Builder<List<NamedExpression>> castedConstants
-                = ImmutableList.builderWithExpectedSize(constantExprsList.size());
-        for (List<NamedExpression> row : constantExprsList) {
+                = ImmutableList.builderWithExpectedSize(rows.size());
+        for (List<NamedExpression> row : rows) {
             ImmutableList.Builder<NamedExpression> castedRow = ImmutableList.builderWithExpectedSize(columnCount);
             for (int i = 0; i < row.size(); i++) {
-                NamedExpression constant = row.get(i);
-                castedRow.add((NamedExpression) constant.withChildren(
-                        TypeCoercionUtils.castIfNotSameTypeStrict(constant, commonDataTypes.get(i))
-                ));
+                NamedExpression constantAlias = row.get(i);
+                DataType commonType = commonDataTypes.get(i);
+                Expression constant = constantAlias.child(0);
+                if (commonType.equals(constant.getDataType())) {
+                    castedRow.add(constantAlias);
+                } else {
+                    Expression expression
+                            = TypeCoercionUtils.castIfNotSameTypeStrict(constant, commonType);
+                    castedRow.add((NamedExpression) constant.withChildren(expression));
+                }
             }
             castedConstants.add(castedRow.build());
         }
-        return Pair.of(castedConstants.build(), nullables);
+        return castedConstants.build();
     }
 }