From 1ba9b85863fae3836ac0e0867466d1c6d58f5e7e Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Mon, 16 Dec 2024 14:58:33 +0800
Subject: [PATCH] branch-3.0: [fix](nereids)EliminateGroupBy rule should keep
 output's datatype unchanged #45359 (#45398)

Cherry-picked from #45359

Co-authored-by: starocean999 <lichi@selectdb.com>
---
 .../doris/nereids/rules/rewrite/EliminateGroupBy.java  | 10 +++-------
 .../nereids/rules/rewrite/EliminateGroupByTest.java    |  1 +
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/EliminateGroupBy.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/EliminateGroupBy.java
index b50d3a41e8c3b5..9325607dd70769 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/EliminateGroupBy.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/EliminateGroupBy.java
@@ -30,7 +30,7 @@
 import org.apache.doris.nereids.trees.expressions.functions.agg.Min;
 import org.apache.doris.nereids.trees.expressions.functions.agg.Sum;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.If;
-import org.apache.doris.nereids.trees.expressions.literal.Literal;
+import org.apache.doris.nereids.trees.expressions.literal.BigIntLiteral;
 import org.apache.doris.nereids.trees.plans.Plan;
 import org.apache.doris.nereids.util.ExpressionUtils;
 import org.apache.doris.nereids.util.PlanUtils;
@@ -84,12 +84,8 @@ public Rule build() {
                                         .castIfNotSameType(f.child(0), f.getDataType()), ne.getName()));
                             } else if (f instanceof Count) {
                                 newOutput.add((NamedExpression) ne.withChildren(
-                                        new If(
-                                            new IsNull(f.child(0)),
-                                            Literal.of(0),
-                                            Literal.of(1)
-                                        )
-                                ));
+                                        new If(new IsNull(f.child(0)), new BigIntLiteral(0),
+                                                new BigIntLiteral(1))));
                             } else {
                                 throw new IllegalStateException("Unexpected aggregate function: " + f);
                             }
diff --git a/fe/fe-core/src/test/java/org/apache/doris/nereids/rules/rewrite/EliminateGroupByTest.java b/fe/fe-core/src/test/java/org/apache/doris/nereids/rules/rewrite/EliminateGroupByTest.java
index 0b6d2f199fc59f..70eb8e4a470746 100644
--- a/fe/fe-core/src/test/java/org/apache/doris/nereids/rules/rewrite/EliminateGroupByTest.java
+++ b/fe/fe-core/src/test/java/org/apache/doris/nereids/rules/rewrite/EliminateGroupByTest.java
@@ -94,6 +94,7 @@ void eliminateCount() {
                         logicalEmptyRelation().when(p -> p.getProjects().get(0).toSql().equals("id")
                                 && p.getProjects().get(1).toSql()
                                 .equals("if(age IS NULL, 0, 1) AS `if(age IS NULL, 0, 1)`")
+                                && p.getProjects().get(1).getDataType().isBigIntType()
                         )
                 );
     }