fixed the bug of join

src/gausskernel/optimizer/prep/prepjointree.cpp

@@ -1181,6 +1181,17 @@ static Node* pull_up_simple_subquery(PlannerInfo* root, Node* jtnode, RangeTblEn
         return jtnode;
     }
 
+    /*
+     * We must flatten any join alias Vars in the subquery's targetlist,
+     * because pulling up the subquery's subqueries might have changed their
+     * expansions into arbitrary expressions, which could affect
+     * pullup_replace_vars' decisions about whether PlaceHolderVar wrappers
+     * are needed for tlist entries.  (Likely it'd be better to do
+     * flatten_join_alias_vars on the whole query tree at some earlier stage,
+     * maybe even in the rewriter; but for now let's just fix this case here.)
+     */
+    subquery->targetList = (List *) flatten_join_alias_vars(subroot, (Node *) subquery->targetList);
+
     /*
      * Adjust level-0 varnos in subquery so that we can append its rangetable
      * to upper query's.  We have to fix the subquery's append_rel_list as

src/test/regress/expected/join_test_alias.out

@@ -0,0 +1,55 @@
+CREATE TABLE t11 (
+sec_code character(6) NOT NULL,
+issue_type character(3) NOT NULL
+);
+CREATE TABLE t22 (
+company_code character(6) NOT NULL,
+list_profit_flag character(1) NOT NULL
+);
+CREATE TABLE t33 (
+company_code character(6) NOT NULL,
+issue_flag character(6) NOT NULL
+);
+insert into t11 values(1,'S04');
+insert into t22 values(1,'Y');
+insert into t33 values(1,'1');
+insert into t33 values(2,'2');
+select
+T5.issue_type
+,T6.is_type
+from
+(
+select T1.sec_code
+,issue_type
+--,case when list_profit_flag='Y' then '是' else '否' end as list_profit_flag
+from
+(
+select sec_code
+,case when issue_type in ('S04','S05','S06','S09') then '增发'
+when issue_type in ('S01','S02') then '首发'
+else '其他' end as issue_type
+from t11
+)T1
+left join
+(
+select list_profit_flag
+,company_code
+from t22
+)T2
+on T1.sec_code=T2.company_code
+)T5
+full join
+(
+SELECT CASE
+WHEN issue_flag = ANY (ARRAY['1'::bpchar, '3'::bpchar, '11'::bpchar]) THEN '首发'::text
+ELSE '增发'::text
+END AS is_type from t33
+)T6
+on T5.issue_type=T6.is_type
+;
+ issue_type | is_type 
+------------+---------
+ 增发       | 增发
+            | 首发
+(2 rows)
+

src/test/regress/parallel_schedule0

@@ -916,3 +916,4 @@ test: fdw_audit
 test: gs_global_config_audit
 test: detail
 test: gs_dump_encrypt
+test: join_test_alias

src/test/regress/sql/join_test_alias.sql

@@ -0,0 +1,53 @@
+CREATE TABLE t11 (
+sec_code character(6) NOT NULL,
+issue_type character(3) NOT NULL
+);
+
+CREATE TABLE t22 (
+company_code character(6) NOT NULL,
+list_profit_flag character(1) NOT NULL
+);
+
+CREATE TABLE t33 (
+company_code character(6) NOT NULL,
+issue_flag character(6) NOT NULL
+);
+
+insert into t11 values(1,'S04');
+insert into t22 values(1,'Y');
+insert into t33 values(1,'1');
+insert into t33 values(2,'2');
+
+select
+T5.issue_type
+,T6.is_type
+from
+(
+select T1.sec_code
+,issue_type
+--,case when list_profit_flag='Y' then '是' else '否' end as list_profit_flag
+from
+(
+select sec_code
+,case when issue_type in ('S04','S05','S06','S09') then '增发'
+when issue_type in ('S01','S02') then '首发'
+else '其他' end as issue_type
+from t11
+)T1
+left join
+(
+select list_profit_flag
+,company_code
+from t22
+)T2
+on T1.sec_code=T2.company_code
+)T5
+full join
+(
+SELECT CASE
+WHEN issue_flag = ANY (ARRAY['1'::bpchar, '3'::bpchar, '11'::bpchar]) THEN '首发'::text
+ELSE '增发'::text
+END AS is_type from t33
+)T6
+on T5.issue_type=T6.is_type
+;