From c34e92b64f43a660dd1636a11d337dd7d28181a5 Mon Sep 17 00:00:00 2001
From: totaj <totaj@qq.com>
Date: Tue, 8 Nov 2022 16:26:31 +0800
Subject: [PATCH] Fix a outer join bug.

---
 .../backend/parser/parse_compatibility.cpp    |  2 +-
 .../expected/a_outerjoin_conversion.out       | 41 +++++++++++++++++++
 .../regress/sql/a_outerjoin_conversion.sql    | 21 ++++++++++
 3 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/src/common/backend/parser/parse_compatibility.cpp b/src/common/backend/parser/parse_compatibility.cpp
index f51ba92f3d..12000c9f66 100644
--- a/src/common/backend/parser/parse_compatibility.cpp
+++ b/src/common/backend/parser/parse_compatibility.cpp
@@ -657,7 +657,7 @@ bool plus_outerjoin_precheck(const OperatorPlusProcessContext* ctx, Node* expr,
         }
 
         /* Report Error when t_noplus and t_hasplus is the same RTE */
-        if (strcmp(t_noplus->eref->aliasname, t_hasplus->eref->aliasname) == 0) {
+        if (t_noplus == t_hasplus) {
             ereport(ERROR,
                 (errcode(ERRCODE_SYNTAX_ERROR),
                     errmsg("\"%s\" is not allowed to outer join with itself.", t_noplus->eref->aliasname)));
diff --git a/src/test/regress/expected/a_outerjoin_conversion.out b/src/test/regress/expected/a_outerjoin_conversion.out
index 7afa87f93b..6e7e21e42b 100644
--- a/src/test/regress/expected/a_outerjoin_conversion.out
+++ b/src/test/regress/expected/a_outerjoin_conversion.out
@@ -1528,6 +1528,47 @@ reset enable_mergejoin;
 reset enable_hashjoin;
 reset enable_seqscan;
 reset enable_index_nestloop;
+--test (+) with itself
+create table public.join_t1(col int, col2 int);
+create schema join_schema;
+create table join_schema.join_t1(col int, col2 int);
+insert into public.join_t1 values(1,11),(2,22);
+insert into join_schema.join_t1 values(1,10);
+--ok
+select * from public.join_t1, join_schema.join_t1  where public.join_t1.col (+)=join_schema.join_t1.col;
+ col | col2 | col | col2 
+-----+------+-----+------
+   1 |   11 |   1 |   10
+(1 row)
+
+select * from public.join_t1 t1, join_schema.join_t1 t2 where t1.col (+)=t2.col;
+ col | col2 | col | col2 
+-----+------+-----+------
+   1 |   11 |   1 |   10
+(1 row)
+
+select * from public.join_t1 t1 ,public.join_t1 t2  where t1.col (+)=t2.col2 order by t2.col;
+ col | col2 | col | col2 
+-----+------+-----+------
+     |      |   1 |   11
+     |      |   2 |   22
+(2 rows)
+
+select * from public.join_t1 t1 ,public.join_t1 t2  where t1.col (+)=t2.col order by t2.col;
+ col | col2 | col | col2 
+-----+------+-----+------
+   1 |   11 |   1 |   11
+   2 |   22 |   2 |   22
+(2 rows)
+
+--fail
+select * from public.join_t1 t1 ,public.join_t1 t2  where t1.col (+)=t1.col;
+ERROR:  "t1" is not allowed to outer join with itself.
+select * from public.join_t1 t1 ,public.join_t1 t2  where t1.col (+)=t1.col2;
+ERROR:  "t1" is not allowed to outer join with itself.
+drop table public.join_t1;
+drop table join_schema.join_t1;
+drop schema join_schema;
 drop view plus_v;
 drop function plus_join_test_1();
 drop table t1;
diff --git a/src/test/regress/sql/a_outerjoin_conversion.sql b/src/test/regress/sql/a_outerjoin_conversion.sql
index 229c6c89a1..62e46319c5 100644
--- a/src/test/regress/sql/a_outerjoin_conversion.sql
+++ b/src/test/regress/sql/a_outerjoin_conversion.sql
@@ -399,6 +399,27 @@ reset enable_hashjoin;
 reset enable_seqscan;
 reset enable_index_nestloop;
 
+--test (+) with itself
+create table public.join_t1(col int, col2 int);
+create schema join_schema;
+create table join_schema.join_t1(col int, col2 int);
+insert into public.join_t1 values(1,11),(2,22);
+insert into join_schema.join_t1 values(1,10);
+
+--ok
+select * from public.join_t1, join_schema.join_t1  where public.join_t1.col (+)=join_schema.join_t1.col;
+select * from public.join_t1 t1, join_schema.join_t1 t2 where t1.col (+)=t2.col;
+select * from public.join_t1 t1 ,public.join_t1 t2  where t1.col (+)=t2.col2 order by t2.col;
+select * from public.join_t1 t1 ,public.join_t1 t2  where t1.col (+)=t2.col order by t2.col;
+
+--fail
+select * from public.join_t1 t1 ,public.join_t1 t2  where t1.col (+)=t1.col;
+select * from public.join_t1 t1 ,public.join_t1 t2  where t1.col (+)=t1.col2;
+
+drop table public.join_t1;
+drop table join_schema.join_t1;
+drop schema join_schema;
+
 drop view plus_v;
 drop function plus_join_test_1();
 drop table t1;
-- 
Gitee