Failing test for ColumnType.Nullable from output of EXPLAIN

[dolmen]

Description

Failing test checking ColumnType.Nullable() with query EXPLAIN SELECT * FROM mysql.user: column Extra is
indicated not nullable, but data contains NULL.

Test code: https://github.com/dolmen/mysql/blob/test-EXPLAIN-nullable/driver_test.go#L2981
Test results on Github Actions: https://github.com/dolmen/mysql/actions/runs/621816893

Apparently the test doesn't fail on MariaDB in Github Actions, so this might be a MySQL bug. But is there a way to detect the case and workaround it?

No fix is provided in this PR.

Checklist

• Code compiles correctly
• Created tests which fail without the change (if possible)
• All tests passing
• Extended the README / documentation, if necessary
• Added myself / the copyright holder to the AUTHORS file

[methane]

Apparently the test doesn't fail on MariaDB in Github Actions, so this might be a MySQL bug.

I don't verified the packet capture, but I think it is a MySQL bug. The driver need to believe result header packet.

But is there a way to detect the case and workaround it?

Use sql.NullString always regardless ColumnType.Nullable(). When it is null, it is null.

Since you didn't describe your use case, that's all I can say.