chore: clean error and useless tests

[xudong963]

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Summary

When I work on #9150, I found some strange and useless tests... 😅

I have some suggestions for tests:

1. For reviewers, we should review tests carefully too.
2. For tests writers, we should focus on test points to avoid useless tests.
3. Consider if tests that you write will be influenced by other files and even become flaky tests.

Closes #issue

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1 Ignored Deployment

Name	Status	Preview	Updated
databend	⬜️ Ignored (Inspect)		Dec 13, 2022 at 3:24PM (UTC)

[xudong963]

Strange..

Any thoughts?

[TCeason]

Strange..

Any thoughts?

Not *.

statement query T
SELECT name FROM system.databases where name = 'a' or name = 'b';

----
a
b

'u1'@mysqldb 22:41:26 [default]> SELECT * FROM system.databases where name = 'a' or name = 'b';
+---------+------+
| catalog | name |
+---------+------+
| default | a    |
| default | b    |
+---------+------+
2 rows in set (0.08 sec)
Read 9 rows, 286.00 B in 0.020 sec., 442.51 rows/sec., 13.73 KiB/sec.

'u1'@mysqldb 22:41:32 [default]> SELECT name FROM system.databases where name = 'a' or name = 'b';
+------+
| name |
+------+
| a    |
| b    |
+------+
2 rows in set (0.06 sec)
Read 9 rows, 286.00 B in 0.016 sec., 545.55 rows/sec., 16.93 KiB/sec.