Documentation Home
MySQL 5.5 Reference Manual
Related Documentation Download this Manual
PDF (US Ltr) - 26.9Mb
PDF (A4) - 26.9Mb
PDF (RPM) - 25.3Mb
HTML Download (TGZ) - 6.3Mb
HTML Download (Zip) - 6.3Mb
HTML Download (RPM) - 5.3Mb
Man Pages (TGZ) - 157.6Kb
Man Pages (Zip) - 260.9Kb
Info (Gzip) - 2.6Mb
Info (Zip) - 2.6Mb
Excerpts from this Manual

10.3.1 Collation Naming Conventions

MySQL collation names follow these conventions:

  • A collation name starts with the name of the character set with which it is associated, generally followed by one or more suffixes indicating other collation characteristics. For example, utf8_general_ci and latin1_swedish_ci are collations for the utf8 and latin1 character sets, respectively. The binary character set has a single collation, also named binary, with no suffixes.

  • A language-specific collation includes a language name. For example, utf8_turkish_ci and utf8_hungarian_ci sort characters for the utf8 character set using the rules of Turkish and Hungarian, respectively.

  • Collation suffixes indicate whether a collation is case and accent sensitive, or binary. The following table shows the suffixes used to indicate these characteristics.

    Table 10.1 Collation Case Sensitivity Suffixes

    Suffix Meaning
    _ai Accent insensitive
    _as Accent sensitive
    _ci Case insensitive
    _cs case-sensitive
    _bin Binary

    For nonbinary collation names that do not specify accent sensitivity, it is determined by case sensitivity. If a collation name does not contain _ai or _as, _ci in the name implies _ai and _cs in the name implies _as. For example, latin1_general_ci is explicitly case insensitive and implicitly accent insensitive, and latin1_general_cs is explicitly case sensitive and implicitly accent sensitive.

    For the binary collation of the binary character set, comparisons are based on numeric byte values. For the _bin collation of a nonbinary character set, comparisons are based on numeric character code values, which differ from byte values for multibyte characters. For more information, see Section 10.8.5, “The binary Collation Compared to _bin Collations”.

  • For Unicode character sets, the xxx_general_mysql500_ci collations preserve the pre-5.1.24 ordering of the original xxx_general_ci collations and permit upgrades for tables created before MySQL 5.1.24 (Bug #27877).


User Comments
User comments in this section are, as the name implies, provided by MySQL users. The MySQL documentation team is not responsible for, nor do they endorse, any of the information provided here.
Sign Up Login You must be logged in to post a comment.