Bug: Chinese/Unicode characters not supported as column aliases in bendsql

[wubx]

Summary

In Databend's MySQL client, the following queries work correctly:

SELECT 'a' AS 中文;
SELECT 'a' 中文;

However, bendsql fails to handle Chinese (Unicode) characters used as unquoted column aliases.

Steps to Reproduce

-- Works in MySQL client connected to Databend
SELECT 'a' AS 中文;
SELECT 'a' 中文;

Try the same in bendsql — it fails to parse or execute correctly.

Expected Behavior

bendsql should support Unicode characters (including Chinese) as column aliases, consistent with Databend's MySQL client behavior.

Actual Behavior

bendsql does not handle Unicode/Chinese unquoted identifiers as column aliases.

Root Cause

Likely a lexer/parser issue in bendsql where identifier character validation does not include Unicode ranges beyond ASCII.

Environment

• Databend: main branch
• bendsql: (0.33.5-94d2cdc71cce4f72cd2bb788fc2686aca7fc9cbf)