Hi,
i change my data folder because it was placed in my apache document root folder. Ich moved the data folder out of it and change the path in the “config.php”. But … can a update overwrite my changes?
By default is the data folder in the folder nextcloud.
A change only in config.php will not recognized, because there are some entries in mysql, which are pointing to nextcloud/data folder.
There is a HowTo how to change data folder to another place:
I prefer solution 2 
FYI: We have a internatiol section with german language:
An update will not overwrite anything inside config.php. If you successfully moved your data folder, it will survive.
Oh thanks 