Permit connection to MariaDB 10.10

[rusher]

Driver cannot even connect to MariaDB 10.10+, connection fails with error :

[InvalidCastException: Object cannot be cast from DBNull to other types.]
System.DBNull.System.IConvertible.ToInt32(IFormatProvider provider) +57
MySql.Data.MySqlClient.Driver.LoadCharacterSets(MySqlConnection connection) +557
MySql.Data.MySqlClient.Driver.Configure(MySqlConnection connection) +200
MySql.Data.MySqlClient.MySqlConnection.Open() +1341

the reason is MariaDB 10.10 supports Unicode 14 with Collations that can have null id/null characters:

show collation where COLLATION like 'uca14%';
+--------------------------------+---------+------+---------+----------+---------+
| Collation                      | Charset | Id   | Default | Compiled | Sortlen |
+--------------------------------+---------+------+---------+----------+---------+
| uca1400_ai_ci                  | NULL    | NULL | NULL    | Yes      |       8 |
| uca1400_ai_cs                  | NULL    | NULL | NULL    | Yes      |       8 |
| uca1400_as_ci                  | NULL    | NULL | NULL    | Yes      |       8 |
| uca1400_as_cs                  | NULL    | NULL | NULL    | Yes      |       8 |
...

Since 10.10, some collation have null id in I_S.COLLATIONS/SHOW COLLATIONS.
ID's only appear in I_S.COLLATION_CHARACTER_SET_APPLICABILITY, associate to charset.
example:

 SELECT * FROM INFORMATION_SCHEMA.COLLATION_CHARACTER_SET_APPLICABILITY WHERE COLLATION_NAME LIKE 'uca1400_ai_ci';
 +----------------+--------------------+-----------------------+------+------------+
 | COLLATION_NAME | CHARACTER_SET_NAME | FULL_COLLATION_NAME   | ID   | IS_DEFAULT |
 +----------------+--------------------+-----------------------+------+------------+
 | uca1400_ai_ci  | utf8mb3            | utf8mb3_uca1400_ai_ci | 2048 |            |
 | uca1400_ai_ci  | ucs2               | ucs2_uca1400_ai_ci    | 2560 |            |
 | uca1400_ai_ci  | utf8mb4            | utf8mb4_uca1400_ai_ci | 2304 |            |
 | uca1400_ai_ci  | utf16              | utf16_uca1400_ai_ci   | 2816 |            |
 | uca1400_ai_ci  | utf32              | utf32_uca1400_ai_ci   | 3072 |            |
 +----------------+--------------------+-----------------------+------+------------+

This simple fix correct this connection problem

[mysql-oca-bot]

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Thanks

[mysql-oca-bot]

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Thanks

[rusher]

I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it.

[unglaublicherdude]

This PR helped us making a hotifx-package into our local nuget repository. I would appreciate having the official fix at nuget.org.
@rusher thank's for the work!

[mysql-oca-bot]

Hi, thank you for your contribution. Your code has been assigned to an internal queue. Please follow
bug http://bugs.mysql.com/bug.php?id=110898 for updates.
Thanks

[alvaromarithompson]

Mysql Connector has become unusable on MariaDB 10.10.1+ without this fix, would appreciate it pushing through to the main release.

Thanks @rusher for the fix.

[perplexityjeff]

Are there any updates regarding this fix?

[JeanRessouche]

Up, this is a blocking issue

[alvaromarithompson]

I doubt anyone's reading this thread, comments are probably better posted on http://bugs.mysql.com/bug.php?id=110898

(I am also awaiting this to make its way to the next release, it's blocking our upgrade to Debian 12)

[bgrainger]

A potential workaround for anyone affected by this bug is to switch to the alternative ADO.NET library: https://github.com/mysql-net/MySqlConnector, https://mysqlconnector.net/tutorials/migrating-from-connector-net/

(Disclaimer: I am the lead author of MySqlConnector)

[alexbn71]

Does MySqlConnector support session parameters?

[bgrainger]

@alexbn71 You should ask questions about MySqlConnector at its repo: https://github.com/mysql-net/MySqlConnector/discussions

(And, yes it does.)

[sistemasIHS]

Alguien sabe si esto, ya entro en alguna version, he intentado cambiar a MySql Connector, pero me genera otro error el cual no he encontrado solucion.

[alvaromarithompson]

Still no fix for this issue.

[rusher]

MariaDB is compatible now, add a trick for MySQL.Data connector (see https://jira.mariadb.org/browse/MDEV-31608) but this need MariaDB 10.11.7+ version, not 10.10

[alvaromarithompson]

It's probably worth moving to MySqlConnector, as quoted in this thread here https://bugs.mysql.com/bug.php?id=109331 the .NET connector from the MySQL Dev team now focuses only on MySQL and not any developments in MariaDB:

MySQL and MariaDB are diverging products and compatibility is no longer guaranteed and is not a common objective of both projects. 
MariaDB is not a drop-in replacement of MySQL anymore.

Storage engines, protocol, etc.. all are going in different directions.

Therefore MySQL Connectors are developed with MySQL Server (Community, Enterprise) focus.

This problem will not be fixed by the official release.