Can't find column errors when using group_concat

[qw4990]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

CREATE TABLE `tx` (
  `ct_name` varchar(100) DEFAULT NULL,
  `employee_name` varchar(100) DEFAULT NULL
);

select group_concat(ct_name_tt order by ct_nums_tt)
from (
  select  ct_name_t as ct_name_tt ,ct_nums_t as ct_nums_tt
  from
      (
      select  t1.ct_name as ct_name_t, t1.ct_name+' ' as ct_nums_t, t1.employee_name
      from (
          select employee_name, ct_name
          from tx
          group by employee_name,ct_name
          ) t1
      ) t
  group by ct_name_t,ct_nums_t
) tt;

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

The query above returns an empty result without any error.

3. What did you see instead (Required)

ERROR 1105 (HY000): Can't find column tt.ct_nums_tt in schema Column: [test.t.ct_name_t,t.ct_nums_t] Unique key: [[test.t.ct_name_t,t.ct_nums_t]]

4. What is your TiDB version? (Required)

Release-3.0.20

mysql> select version();
+---------------------+
| version()           |
+---------------------+
| 5.7.25-TiDB-v3.0.20 |
+---------------------+
1 row in set (0.00 sec)

[TszKitLo40]

In master version, the result is NULL. It seems that this issue has been fixed.

[XuHuaiyu]

@qw4990 Maybe we need to check which commit in master fixed this issue.

[yudongusa]

@qw4990 @XuHuaiyu since it's been quite awhile after this was fixed and probably hard to locate the PR actually fixed the issue, should we go ahead to close it?

[winoros]

Since 3.0.x is not maintained now. We are going to close this issue.
If you meet this one, upgrading would solve it. :)

[github-actions]

Please check whether the issue should be labeled with 'affects-x.y' or 'fixes-x.y.z', and then remove 'needs-more-info' label.