nextcloud_ynh
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YunoHost-Apps
Migrate mysql db to utf8
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- Description of why you made this PR
Solution
- Fix https://github.com/YunoHost-Apps/nextcloud_ynh/pull/384
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While you're at it, I would suggest to change charset to utf8mb4 : utf8 is an alias for utf8mb3, which is the UTF-8 subset of characters that are at most 3 bytes long. utf8mb4, on the other side, cant represent any UTF-8 value.
edit: and many thanks for all the work done here :) .
Passing by following this discussion : https://github.com/YunoHost/yunohost/pull/1284#issuecomment-906758754
Basically our my.cnf is super old, modern debian conf has character-set-server = utf8mb4 but we ain't using it ... I'm quite tempted to look into implementing a DB general migration in Yunohost (for example during the buster->bullseye transition) - assuming it's "just" about running a ALTER DATABASE $db_name CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;
That would prevent nextcloud from having to implement super custom login about specifying the character set all over the place ... and apparently seafile needs this too.
(By the way I was having a look into this for migrations in the core yesterday, turns out the ALTER DATABASE only changes the default charset for new tables but doesn't change any existing table ... Theres also a similar ALTER TABLE instruction which is only meaningful if the table content is already encoded with the appropriate charset and doesn't magically migrate the thing ... but afaik in the context of Nextcloud, exec_occ db:convert-mysql-charset does precisely all the re-encoding ? ... but in the general case there's no magic solution for any DB)
I'm not sure to understand... @alexAubin Is it possible to migrate the database to utf8mb4? Will be done during migration do bullseyes?
Hello,
Any news about that ? I might be running into issues because of that non-UT8 character set for another app (FreshRSS https://github.com/FreshRSS/FreshRSS/issues/4139) and I wonder if that's a change I need to do for all databases or if they are independents in some way.
Thanks in advance :)
I think this PR will be obsolete after the Bullseye migration if I understood correctly.
Eeeeh not exactly because the new config only affects newly create tables. For old one, one still has to convert the content of the table, which is not a trivial operation and is apparently app-specific (you can't just take any random SQL DB and convert it). This is why the exec_occ db:convert-mysql-charset exists and handles the reencoding.
But in my experience for Nextcloud, this conversion is likely to fail. IDK what to do with that.
Does that mean old yunohost nextcloud won't be able to migrate mysql to utf8?
Looks like the official procedure has slightly changed in Nextcloud 22 (notably, rather use of maintenance:repair command instead of db:convert-mysql-charset). Maybe that migration could be more robust/reliable...?
