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sql-statement-show-collation.md

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SHOW COLLATION | TiDB SQL Statement Reference
An overview of the usage of SHOW COLLATION for the TiDB database.
/docs/dev/sql-statements/sql-statement-show-collation/
/docs/dev/reference/sql/statements/show-collation/

SHOW COLLATION

This statement provides a static list of collations, and is included to provide compatibility with MySQL client libraries.

Note:

Results of SHOW COLLATION vary when the "new collation framework" is enabled. For new collation framework details, refer to Character Set and Collation.

Synopsis

ShowCollationStmt ::=
    "SHOW" "COLLATION" ShowLikeOrWhere?

ShowLikeOrWhere ::=
    "LIKE" SimpleExpr
|   "WHERE" Expression

Examples

When the new collation framework is enabled (the default), the example output is as follows:

SHOW COLLATION;
+--------------------+---------+-----+---------+----------+---------+---------------+
| Collation          | Charset | Id  | Default | Compiled | Sortlen | Pad_attribute |
+--------------------+---------+-----+---------+----------+---------+---------------+
| ascii_bin          | ascii   |  65 | Yes     | Yes      |       1 | PAD SPACE     |
| binary             | binary  |  63 | Yes     | Yes      |       1 | NO PAD        |
| gbk_bin            | gbk     |  87 |         | Yes      |       1 | PAD SPACE     |
| gbk_chinese_ci     | gbk     |  28 | Yes     | Yes      |       1 | PAD SPACE     |
| latin1_bin         | latin1  |  47 | Yes     | Yes      |       1 | PAD SPACE     |
| utf8_bin           | utf8    |  83 | Yes     | Yes      |       1 | PAD SPACE     |
| utf8_general_ci    | utf8    |  33 |         | Yes      |       1 | PAD SPACE     |
| utf8_unicode_ci    | utf8    | 192 |         | Yes      |       8 | PAD SPACE     |
| 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     |
+--------------------+---------+-----+---------+----------+---------+---------------+
13 rows in set (0.00 sec)

When the new collation framework is disabled, only binary collations are listed.

SHOW COLLATION;
+-------------+---------+----+---------+----------+---------+---------------+
| Collation   | Charset | Id | Default | Compiled | Sortlen | Pad_attribute |
+-------------+---------+----+---------+----------+---------+---------------+
| utf8mb4_bin | utf8mb4 | 46 | Yes     | Yes      |       1 | PAD SPACE     |
| latin1_bin  | latin1  | 47 | Yes     | Yes      |       1 | PAD SPACE     |
| binary      | binary  | 63 | Yes     | Yes      |       1 | NO PAD        |
| ascii_bin   | ascii   | 65 | Yes     | Yes      |       1 | PAD SPACE     |
| utf8_bin    | utf8    | 83 | Yes     | Yes      |       1 | PAD SPACE     |
| gbk_bin     | gbk     | 87 | Yes     | Yes      |       1 | PAD SPACE     |
+-------------+---------+----+---------+----------+---------+---------------+
6 rows in set (0.00 sec)

To filter on the character set, you can add a WHERE clause.

SHOW COLLATION WHERE Charset="utf8mb4";
+--------------------+---------+-----+---------+----------+---------+
| Collation          | Charset | Id  | Default | Compiled | Sortlen |
+--------------------+---------+-----+---------+----------+---------+
| utf8mb4_0900_ai_ci | utf8mb4 | 255 |         | Yes      |       1 |
| utf8mb4_0900_bin   | utf8mb4 | 309 |         | Yes      |       1 |
| utf8mb4_bin        | utf8mb4 |  46 | Yes     | Yes      |       1 |
| utf8mb4_general_ci | utf8mb4 |  45 |         | Yes      |       1 |
| utf8mb4_unicode_ci | utf8mb4 | 224 |         | Yes      |       1 |
+--------------------+---------+-----+---------+----------+---------+
5 rows in set (0.00 sec)

MySQL compatibility

The usage of the SHOW COLLATION statement in TiDB is fully compatible with MySQL. However, charsets in TiDB might have different default collations compared with MySQL. For details, refer to Compatibility with MySQL. If you find any compatibility differences, report a bug.

See also