MySQL Bugs: #103665 The aliases interferes despite the fact that the database is specified

[ChenPeng2013]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

CREATE DATABASE db1;
CREATE TABLE db1.t(a INT);
INSERT INTO db1.t VALUES (1);
UPDATE db1.t, (SELECT 1 AS a) AS t SET db1.t.a=2;
UPDATE (SELECT 1 AS a) AS t, db1.t SET db1.t.a=2;

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

update succeeded

3. What did you see instead (Required)

mysql> UPDATE db1.t, (SELECT 1 AS a) AS t SET db1.t.a=2;
ERROR 1288 (HY000): The target table t of the UPDATE is not updatable
mysql> UPDATE (SELECT 1 AS a) AS t, db1.t SET db1.t.a=2;
ERROR 1288 (HY000): The target table t of the UPDATE is not updatable

4. What is your TiDB version? (Required)

Release Version: v4.0.0-beta.2-2832-gc6c8265e0-dirty
Edition: Community
Git Commit Hash: c6c8265e098b65339a85be2e35678b1c13f0f53a
Git Branch: master
UTC Build Time: 2021-05-10 14:58:41
GoVersion: go1.13
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false

[AilinKid]

this issue is fixed by:

commit e92df20 (HEAD)
Author: xiongjiwei xiongjiwei1996@outlook.com
Date: Fri May 14 19:09:38 2021 +0800
planner: fix wrongly check for update statement (#24614)

And this PR is refactored by #30061 which is more clear, so let's cherry-pick 30061 if necessary

[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.