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(11) | YES | | NULL | |
| IS_DEFAULT | varchar(3) | YES | | NULL | |
| IS_COMPILED | varchar(3) | YES | | NULL | |
| SORTLEN | bigint(3) | YES | | NULL | |
+--------------------+-------------+------+------+---------+-------+
6 rows in set (0.00 sec)
SELECT * FROM collations WHERE character_set_name='utf8mb4';
+--------------------+--------------------+------+------------+-------------+---------+
| COLLATION_NAME | CHARACTER_SET_NAME | ID | IS_DEFAULT | IS_COMPILED | SORTLEN |
+--------------------+--------------------+------+------------+-------------+---------+
| utf8mb4_bin | utf8mb4 | 46 | Yes | Yes | 1 |
| utf8mb4_general_ci | utf8mb4 | 45 | | Yes | 1 |
| utf8mb4_unicode_ci | utf8mb4 | 224 | | Yes | 1 |
+--------------------+--------------------+------+------------+-------------+---------+
3 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.