COLLATIONS

The COLLATIONS table provides a list of collations that correspond to character sets in the CHARACTER_SETS table. Currently, this table is included only for compatibility with MySQL.

USE information_schema;
DESC collations;

+--------------------+-------------+------+------+---------+-------+
| Field              | Type        | Null | Key  | Default | Extra |
+--------------------+-------------+------+------+---------+-------+
| COLLATION_NAME     | varchar(32) | YES  |      | NULL    |       |
| CHARACTER_SET_NAME | varchar(32) | YES  |      | NULL    |       |
| ID                 | bigint      | YES  |      | NULL    |       |
| IS_DEFAULT         | varchar(3)  | YES  |      | NULL    |       |
| IS_COMPILED        | varchar(3)  | YES  |      | NULL    |       |
| SORTLEN            | bigint      | YES  |      | NULL    |       |
| PAD_ATTRIBUTE      | varchar(9)  | YES  |      | NULL    |       |
+--------------------+-------------+------+------+---------+-------+
7 rows in set (0.001 sec)

SELECT * FROM collations WHERE character_set_name='utf8mb4';

+--------------------+--------------------+------+------------+-------------+---------+---------------+
| COLLATION_NAME     | CHARACTER_SET_NAME | ID   | IS_DEFAULT | IS_COMPILED | SORTLEN | PAD_ATTRIBUTE |
+--------------------+--------------------+------+------------+-------------+---------+---------------+
| utf8mb4_0900_ai_ci | utf8mb4            |  255 |            | Yes         |       0 | NO PAD        |
| utf8mb4_0900_bin   | utf8mb4            |  309 |            | Yes         |       1 | NO PAD        |
| utf8mb4_bin        | utf8mb4            |   46 | Yes        | Yes         |       1 | PAD SPACE     |
| utf8mb4_general_ci | utf8mb4            |   45 |            | Yes         |       1 | PAD SPACE     |
| utf8mb4_unicode_ci | utf8mb4            |  224 |            | Yes         |       8 | PAD SPACE     |
+--------------------+--------------------+------+------------+-------------+---------+---------------+
5 rows in set (0.001 sec)

The description of columns in the COLLATIONS table is as follows:

• COLLATION_NAME: The name of the collation.
• CHARACTER_SET_NAME: The name of the character set which the collation belongs to.
• ID: The ID of the collation.
• IS_DEFAULT: Whether this collation is the default collation of the character set it belongs to.
• IS_COMPILED: Whether the character set is compiled into the server.
• SORTLEN: The minimum length of memory allocated when the collation sorts characters.
• PAD_ATTRIBUTE: Whether trailing spaces are ignored during string comparison. PAD SPACE means that trailing spaces are ignored (for example, 'abc' equals 'abc '), while NO PAD means that trailing spaces are significant (for example, 'abc' does not equal 'abc ').

See also

• SHOW CHARACTER SET
• SHOW COLLATION
• INFORMATION_SCHEMA.CHARACTER_SETS
• INFORMATION_SCHEMA.COLLATION_CHARACTER_SET_APPLICABILITY