10.13.2 Choosing a Collation ID

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Each collation must have a unique ID. To add a collation, you must choose an ID value that is not currently used. MySQL supports two-byte collation IDs. The range of IDs from 1024 to 2047 is reserved for user-defined collations. The collation ID that you choose will appear in these contexts:

The ID column of the INFORMATION_SCHEMA.COLLATIONS table.
The Id column of SHOW COLLATION output.
The charsetnr member of the MYSQL_FIELD C API data structure.
The number member of the MY_CHARSET_INFO data structure returned by the mysql_get_character_set_info() C API function.

To determine the largest currently used ID, issue the following statement:

mysql> SELECT MAX(ID) FROM INFORMATION_SCHEMA.COLLATIONS;
+---------+
| MAX(ID) |
+---------+
| 210 |
+---------+

To display a list of all currently used IDs, issue this statement:

mysql> SELECT ID FROM INFORMATION_SCHEMA.COLLATIONS ORDER BY ID;
+-----+
| ID |
+-----+
| 1 |
| 2 |
| ... |
| 52 |
| 53 |
| 57 |
| 58 |
| ... |
| 98 |
| 99 |
| 128 |
| 129 |
| ... |
| 210 |
+-----+

Warning

Before upgrading, you should save the configuration files that you change. If you upgrade in place, the process will replace the your modified files.

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Document created the 26/06/2006, last modified the 26/10/2018
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References

Manuel MySQL : https://dev.mysql.com/

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