Home/ Questions/Q 8565401
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-11T17:25:07+00:00

I have the following query in MySQL: SELECT id FROM unicode WHERE `character` =

  • 0

I have the following query in MySQL:

SELECT id FROM unicode WHERE `character` = 'a'

The table unicode contains each unicode character along with an ID (it’s integer encoding value). Since the collation of the table is set to utf8_unicode_ci, I would have expected the above query to only return 97 (the letter ‘a’). Instead, it returns 119 rows containing the IDs of many ‘a’-like letters:

a A Ã …

It seems to be ignoring both case and the multi-byte nature of the characters.

Any ideas?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    As documented under Unicode Character Sets:

    MySQL implements the xxx_unicode_ci collations according to the Unicode Collation Algorithm (UCA) described at http://www.unicode.org/reports/tr10/. The collation uses the version-4.0.0 UCA weight keys: http://www.unicode.org/Public/UCA/4.0.0/allkeys-4.0.0.txt.

    The full collation chart makes clear that, in this collation, most variations of a base letter are equivalent irrespective of their lettercase or accent/decoration.

    If you want to only match exact letters, you should use a binary collation such as utf8_bin.

    • 0