Which UTF-8 Collation (General CI, Unicode CI, or Binary) Should I Choose for User-Submitted Content?

UTF-8 Collation for User-Submitted Content

When storing user-submitted content, determining the appropriate collation for optimal performance and data integrity is crucial. This article examines the differences between UTF-8 General CI (Case-Insensitive), UTF-8 Unicode CI, and UTF-8 Binary to guide you in selecting the most suitable collation.

UTF-8 General vs. UTF-8 Unicode CI

For user-submitted content, UTF-8 General CI is generally recommended over UTF-8 Unicode CI. UTF-8 General CI offers faster operations (such as comparisons) but sacrifices some accuracy compared to UTF-8 Unicode CI.

The primary distinction between the two collations lies in their handling of character equivalence. UTF-8 Unicode CI supports expansions, contractions, and ignorable characters, which can lead to unexpected results in certain comparisons (e.g., German "ß" compares as equal to "ss"). In contrast, UTF-8 General CI performs straightforward one-to-one character comparisons.

UTF-8 Binary for Case-Sensitive Comparisons

UTF-8 Binary is an alternative collation that differs significantly from UTF-8 General and UTF-8 Unicode. It does not perform case-insensitive comparisons and instead compares the raw binary values of characters. This makes it suitable for situations where case-sensitivity is crucial, such as storing passwords, cryptographic keys, or other binary data.

Example Use Cases

• UTF-8 General CI: User-generated content, full-text search
• UTF-8 Unicode CI: Language-specific data, complex character equivalence handling
• UTF-8 Binary: Passwords, cryptographic keys, binary file storage

The above is the detailed content of Which UTF-8 Collation (General CI, Unicode CI, or Binary) Should I Choose for User-Submitted Content?. For more information, please follow other related articles on the PHP Chinese website!