ambiguous column in join condition is not resulting error in tidb

[ramanich1]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

drop table if exists t1,t2,t3,t4;
create table t1 (c int, b int);
create table t2 (a int, b int);
create table t3 (b int, c int);
create table t4 (y int, c int);

select * from t1 natural join (t3 cross join t4);
select * from (t3 cross join t4) natural join t1;
select * from (t1 join t2 on t1.b=t2.b) natural join (t3 natural join t4);
select * from  (t3 natural join t4) natural join (t1 join t2 on t1.b=t2.b);

2. What did you expect to see? (Required)

mysql> select * from t1 natural join (t3 cross join t4);
ERROR 1052 (23000): Column 'c' in from clause is ambiguous
mysql> select * from (t3 cross join t4) natural join t1;
ERROR 1052 (23000): Column 'c' in from clause is ambiguous
mysql> select * from (t1 join t2 on t1.b=t2.b) natural join (t3 natural join t4);
ERROR 1052 (23000): Column 'b' in from clause is ambiguous
mysql> select * from  (t3 natural join t4) natural join (t1 join t2 on t1.b=t2.b);
ERROR 1052 (23000): Column 'b' in from clause is ambiguous

3. What did you see instead (Required)

mysql> 
mysql> select * from t1 natural join (t3 cross join t4);
Empty set (0.00 sec)

mysql> select * from (t3 cross join t4) natural join t1;
Empty set (0.00 sec)

mysql> select * from (t1 join t2 on t1.b=t2.b) natural join (t3 natural join t4);
Empty set (0.00 sec)

mysql> select * from  (t3 natural join t4) natural join (t1 join t2 on t1.b=t2.b);
Empty set (0.00 sec)

4. What is your TiDB version? (Required)

| Release Version: v5.5.0-alpha-168-g23f7e51ae
Edition: Community
Git Commit Hash: 23f7e51ae01287fa7f811e1462d8987e4d7727a4
Git Branch: master
UTC Build Time: 2022-01-27 17:39:21
GoVersion: go1.17.2
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false |