Version number: unknown, cannot be retrieved
Operating System: Windows 10
I cannot start my partition with Windows 10, but I have an image which I can mount in ubuntu. There are some errors in the image, but most of the data is there.
I now try to retrieve my data from Joplin. Where does Joplin save all the data in Windows 10 and can I somehow use them in a new computer? I am thinking about copying the .md files and importing them.
It's in your user profile dir: <user home>/.config/joplin-desktop. Unless you were using the portable version in which case it'll be in JoplinProfile right next to the .exe file.
The notes are stored locally in the profile folder in a database (database.sqlite), not as individual md files.
If you are able to copy out the entireC:\Users\<username>\.config\joplin-desktop folder try replacing the joplin-deskop folder in the new machine with the one from the old machine. Just ensure that you have fully quit Joplin on the new machine before you do this.
I use Joplin's AppImage as well. It seems that there may be more than one unofficial snap package maintainer. However this post from one of them gives some information regarding the profile folder location for their package.
I think you may be using @james-carroll 's version as he recently got permission to use joplin-desktop as the package name.
It's either $HOME/snap/joplin-desktop/current/.config/.joplin-desktop or $HOME/snap/joplin-desktop/current/.config/joplin-desktop, I'm not at a machine right now to check myself, the only difference in the two is the . in the deepest folder, though if Roman says his doesn't have the fullstop then I imagine its the second one.