MySQL 5.7 Release Notes
MySQL Server supports multiple character sets. To display the
available character sets, use the
INFORMATION_SCHEMA
CHARACTER_SETS table or the
SHOW CHARACTER SET statement. A
partial listing follows. For more complete information, see
Section 10.1.10, “Supported Character Sets and Collations”.
mysql> SHOW CHARACTER SET;
+----------+---------------------------------+---------------------+--------+
| Charset | Description | Default collation | Maxlen |
+----------+---------------------------------+---------------------+--------+
| big5 | Big5 Traditional Chinese | big5_chinese_ci | 2 |
...
| latin1 | cp1252 West European | latin1_swedish_ci | 1 |
| latin2 | ISO 8859-2 Central European | latin2_general_ci | 1 |
...
| utf8 | UTF-8 Unicode | utf8_general_ci | 3 |
| ucs2 | UCS-2 Unicode | ucs2_general_ci | 2 |
...
| utf8mb4 | UTF-8 Unicode | utf8mb4_general_ci | 4 |
...
| binary | Binary pseudo charset | binary | 1 |
...
By default, the SHOW CHARACTER
SET statement displays all available character sets.
It takes an optional LIKE or
WHERE clause that indicates which character
set names to match. For example:
mysql> SHOW CHARACTER SET LIKE 'latin%';
+---------+-----------------------------+-------------------+--------+
| Charset | Description | Default collation | Maxlen |
+---------+-----------------------------+-------------------+--------+
| latin1 | cp1252 West European | latin1_swedish_ci | 1 |
| latin2 | ISO 8859-2 Central European | latin2_general_ci | 1 |
| latin5 | ISO 8859-9 Turkish | latin5_turkish_ci | 1 |
| latin7 | ISO 8859-13 Baltic | latin7_general_ci | 1 |
+---------+-----------------------------+-------------------+--------+
A given character set always has at least one collation, and
most character sets have several. To list the display collations
for a character set, use the
INFORMATION_SCHEMA
COLLATIONS table or the
SHOW COLLATION statement.
By default, the SHOW COLLATION
statement displays all available collations. It takes an
optional LIKE or
WHERE clause that indicates which collation
names to display. For example, to see the collations for the
latin1 (cp1252 West European) character set,
use this statement:
mysql> SHOW COLLATION WHERE Charset = 'latin1';
+-------------------+---------+----+---------+----------+---------+
| Collation | Charset | Id | Default | Compiled | Sortlen |
+-------------------+---------+----+---------+----------+---------+
| latin1_german1_ci | latin1 | 5 | | Yes | 1 |
| latin1_swedish_ci | latin1 | 8 | Yes | Yes | 1 |
| latin1_danish_ci | latin1 | 15 | | Yes | 1 |
| latin1_german2_ci | latin1 | 31 | | Yes | 2 |
| latin1_bin | latin1 | 47 | | Yes | 1 |
| latin1_general_ci | latin1 | 48 | | Yes | 1 |
| latin1_general_cs | latin1 | 49 | | Yes | 1 |
| latin1_spanish_ci | latin1 | 94 | | Yes | 1 |
+-------------------+---------+----+---------+----------+---------+
The latin1 collations have the following
meanings.
| Collation | Meaning |
|---|---|
latin1_bin | Binary according to latin1 encoding |
latin1_danish_ci | Danish/Norwegian |
latin1_general_ci | Multilingual (Western European) |
latin1_general_cs | Multilingual (ISO Western European), case sensitive |
latin1_german1_ci | German DIN-1 (dictionary order) |
latin1_german2_ci | German DIN-2 (phone book order) |
latin1_spanish_ci | Modern Spanish |
latin1_swedish_ci | Swedish/Finnish |
Collations have these general characteristics:
Two different character sets cannot have the same collation.
Each character set has a default collation. For example, the default collations for
latin1andutf8arelatin1_swedish_ciandutf8_general_ci, respectively. TheINFORMATION_SCHEMACHARACTER_SETStable and theSHOW CHARACTER SETstatement indicate the default collation for each character set. TheINFORMATION_SCHEMACOLLATIONStable and theSHOW COLLATIONstatement have a column that indicates for each collation whether it is the default for its character set (Yesif so, empty if not).Collation names start with the name of the character set with which they are associated, generally followed by one or more suffixes indicating other collation characteristics. For additional information about naming conventions, see Section 10.1.3.1, “Collation Naming Conventions”.
When a character set has multiple collations, it might not be clear which collation is most suitable for a given application. To avoid choosing an inappropriate collation, perform some comparisons with representative data values to make sure that a given collation sorts values the way you expect.