MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
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 10.10, “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 default character set,
latin1
(cp1252 West European), 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
latin1
and utf8
are
latin1_swedish_ci
and
utf8_general_ci
, respectively. The
INFORMATION_SCHEMA
CHARACTER_SETS
table and the
SHOW CHARACTER SET
statement
indicate the default collation for each character set. The
INFORMATION_SCHEMA
COLLATIONS
table and the
SHOW COLLATION
statement have a
column that indicates for each collation whether it is the
default for its character set (Yes
if 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 10.3.1, “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.