From d98abb12f984017d58084cbf37f2a2bc56bbd664 Mon Sep 17 00:00:00 2001
From: morrySnow <101034200+morrySnow@users.noreply.github.com>
Date: Tue, 17 Jan 2023 11:41:41 +0800
Subject: [PATCH] [fix](Nereids)set oepration type coercion is diff with legacy
 planner (#15982)

---
 .../plans/logical/LogicalSetOperation.java    | 26 +++++++------------
 .../data/nereids_syntax_p0/set_operation.out  | 26 +++++++++++--------
 .../nereids_syntax_p0/set_operation.groovy    |  9 +++++++
 3 files changed, 33 insertions(+), 28 deletions(-)

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/logical/LogicalSetOperation.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/logical/LogicalSetOperation.java
index 1e69cda49c..ef72488816 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/logical/LogicalSetOperation.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/logical/LogicalSetOperation.java
@@ -17,6 +17,7 @@
 
 package org.apache.doris.nereids.trees.plans.logical;
 
+import org.apache.doris.catalog.Type;
 import org.apache.doris.nereids.memo.GroupExpression;
 import org.apache.doris.nereids.properties.LogicalProperties;
 import org.apache.doris.nereids.trees.expressions.Cast;
@@ -129,25 +130,16 @@ public abstract class LogicalSetOperation extends AbstractLogicalPlan implements
         List<Expression> newRightOutpus = new ArrayList<>();
         // Ensure that the output types of the left and right children are consistent and expand upward.
         for (int i = 0; i < resetNullableForLeftOutputs.size(); ++i) {
-            boolean hasPushed = false;
             Slot left = resetNullableForLeftOutputs.get(i);
             Slot right = child(1).getOutput().get(i);
-            if (TypeCoercionUtils.canHandleTypeCoercion(left.getDataType(), right.getDataType())) {
-                Optional<DataType> tightestCommonType =
-                        TypeCoercionUtils.findTightestCommonType(null, left.getDataType(), right.getDataType());
-                if (tightestCommonType.isPresent()) {
-                    Expression newLeft = TypeCoercionUtils.castIfNotSameType(left, tightestCommonType.get());
-                    Expression newRight = TypeCoercionUtils.castIfNotSameType(right, tightestCommonType.get());
-                    newLeftOutputs.add(newLeft);
-                    newRightOutpus.add(newRight);
-                    hasPushed = true;
-                }
-            }
-
-            if (!hasPushed) {
-                newLeftOutputs.add(left);
-                newRightOutpus.add(right);
-            }
+            DataType compatibleType = DataType.convertFromCatalogDataType(Type.getAssignmentCompatibleType(
+                    left.getDataType().toCatalogDataType(),
+                    right.getDataType().toCatalogDataType(),
+                    false));
+            Expression newLeft = TypeCoercionUtils.castIfNotSameType(left, compatibleType);
+            Expression newRight = TypeCoercionUtils.castIfNotSameType(right, compatibleType);
+            newLeftOutputs.add(newLeft);
+            newRightOutpus.add(newRight);
         }
 
         List<List<Expression>> resultExpressions = new ArrayList<>();
diff --git a/regression-test/data/nereids_syntax_p0/set_operation.out b/regression-test/data/nereids_syntax_p0/set_operation.out
index 91b5c554a8..09b3124475 100644
--- a/regression-test/data/nereids_syntax_p0/set_operation.out
+++ b/regression-test/data/nereids_syntax_p0/set_operation.out
@@ -406,31 +406,31 @@ d	d	3
 3	9.0	3	9
 
 -- !union30 --
-1.00	2.0
-1.01	2.0
-0.00	0.0
+1.0000	2.0000000
+1.0100	2.0000000
+0.0001	1E-7
 
 -- !union31 --
 1	2
 hell0	
 
 -- !union32 --
-1.0	2.0
+1.00000000	2.00000
 
 -- !union33 --
-1.0	2.0
+1.00000000	2.00000
 
 -- !union34 --
-1.0	2.0
-1.0	2.0
-1.0	2.0
+1.00000000	2.00000
+1.00000000	2.00000
+1.00000000	2.00000
 
 -- !union35 --
-1.0	2.0
-1.0	2.0
+1.00000000	2.00000
+1.00000000	2.00000
 
 -- !union36 --
-1.0	2.0
+1.00000000	2.00000
 
 -- !union38 --
 2016-07-01
@@ -585,3 +585,7 @@ hell0
 2020-05-25
 2020-05-25
 
+-- !union44 --
+2020-05-25
+2020-05-25 00
+
diff --git a/regression-test/suites/nereids_syntax_p0/set_operation.groovy b/regression-test/suites/nereids_syntax_p0/set_operation.groovy
index d8820e95b5..bc2e86db2f 100644
--- a/regression-test/suites/nereids_syntax_p0/set_operation.groovy
+++ b/regression-test/suites/nereids_syntax_p0/set_operation.groovy
@@ -277,4 +277,13 @@ suite("test_nereids_set_operation") {
     """
 
     qt_union43 """select '2020-05-25' day from test_table union all select day from test_table;"""
+    
+    qt_union44 """
+        select * from
+            (select day from test_table
+            union all
+            select DATE_FORMAT(day, '%Y-%m-%d %H') dt_h from test_table
+            ) a
+        order by 1
+    """
 }