Improvement(query): fix datatype different cause mysql session distroy

[TCeason]

I hereby agree to the terms of the CLA available at: https://databend.rs/dev/policies/cla/

Summary

fix datatype different cause mysql session distroy.

Before Sundy's pr fix #5980 NULLIF function could cause MySQL session destory.

Because in Series::check_get(col)?; return a err and

1. not finish the RowWriter.
2. server does not send anything to the client.

So should use match arm, if find the expr return Err(e) , finish the RowWriter and then return Ok(()).

BTW, we should return Ok(()) because we should not destory the session when cause these err.

Test

I has already rollback Sundy's pr and then test on my laptop. But I don't know how to test the pr on the newest commit version.

'root'@mysqldb 21:27:39 [(none)]> set enable_planner_v2=1;
Query OK, 0 rows affected (0.03 sec)
Read 0 rows, 0.00 B in 0.002 sec., 0 rows/sec., 0.00 B/sec.

'root'@mysqldb 21:27:48 [(none)]> SELECT NULLIF(1, 1);
ERROR 1105 (HY000): Code: 1058, displayText = downcast column error, column type: "Null", expected column: "common_datavalues::columns::nullable::NullableColumn".
'root'@mysqldb 21:27:50 [(none)]> SELECT NULLIF(1, 1);
ERROR 1105 (HY000): Code: 1058, displayText = downcast column error, column type: "Null", expected column: "common_datavalues::columns::nullable::NullableColumn".
'root'@mysqldb 21:27:51 [(none)]> SELECT NULLIF(1, 1);
ERROR 1105 (HY000): Code: 1058, displayText = downcast column error, column type: "Null", expected column: "common_datavalues::columns::nullable::NullableColumn".

Changelog

• Improvement

Related Issues

Fixes #5959

#5959 (comment)

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

1 Ignored Deployment

Name	Status	Preview	Updated
databend	⬜️ Ignored (Inspect)		Jun 22, 2022 at 3:32PM (UTC)

[mergify]

Thanks for the contribution!
I have applied any labels matching special text in your PR Changelog.

Please review the labels and make any necessary changes.