How Can I Perform Accent-Sensitive Searches in MySQL?

Accent-Sensitive MySQL Searches: A Comprehensive Guide

Accent sensitivity can pose challenges in MySQL queries, particularly when searching for characters with diacritics. This article explores the nuances of accent-sensitive queries in MySQL and provides practical solutions.

Problems with Accent-Insensitive Queries

Consider two entries in a UTF-8 table: "abad" and "abád". A query searching for "abád" may also return "abad" due to accent-insensitivity in the default collation.

Solutions

1. Column Collation

To ensure accent sensitivity, specify a collation that differentiates between accented and unaccented characters. For example:

ALTER TABLE words MODIFY `word` VARCHAR(10) COLLATE utf8_bin;

2. BINARY Operator

When searching for an exact match of an accented word, use the BINARY operator:

SELECT * FROM `words` WHERE BINARY `word` = 'abád';

3. COLLATE Clause

In MySQL 8.0 and later, the COLLATE clause allows you to specify a specific collation for a comparison:

SELECT * FROM `words` WHERE `word` = 'abád' COLLATE utf8mb4_bin;

4. Language-Specific Collations

For cases where the language requires specific accent handling, consider using language-specific collations such as utf8_polish_ci or latin1_swedish_ci.

Additional Notes

• The BINARY operator only compares the actual byte values and is case-sensitive.
• The COLLATE clause takes precedence over the column collation.
• When converting data to another collation, use the CONVERT() function.
• MySQL 8.0 uses utf8mb4 as the default character set, which supports a wider range of characters and is recommended over utf8.

By implementing these solutions, you can achieve the desired accent sensitivity in your MySQL queries, ensuring accurate search results for accented characters.

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