How to set up multi user configuration?

[rai.moed at web.de]

Hello all,

I am have installed digikam-5.3.0-01-x86-64.appimage on 2 linux clients
(Linux Mint) and both clients are configured to access my LAN server
(RaspberryPi - Jessie), where all photos are stored.
Digikam is set up with MySQL and the remote folders are connected to the
clients via sshfs.
Everything is working well so far.

I have 3 different folders at the LAN server and access rights like this:

drwxrwxrwx 13   client1 client1   4096 Nov 30 09:23   family_collection
drwx------        4   client1 client1   4096 Nov 26 23:12   c1_collection
drwx------      26   client2 client2   4096 Nov 29 13:54   c2_collection

First I tested a setup with 1 shared database for both clients, but then
private thumbnails are displayed to the other client and searches apply
to all collections, although the actual photos are not accessible.

To keep the private collections fully separated, I decided to to run 2
separate databases.

for client1:
  MySQL:
    database: digikam1
    user: digikam1
  Collections (directories):
    family_collection
    c1_collection

for client2:
  MySQL:
    database: digikam2
    user: digikam2
  Collections (directories):
    family_collection
    c2_collection

But though I think this is not a very reliable setup as the shared
family_collection will be modified by either client and the database of
the other client becomes inconsistent with the files.

So I am looking for a way to improve this.

Does anyone have an idea of how to modify mysql and/or digikam so
multiple users can access only their private collections and the shared
collections as well?

Thank you for your suggestions and best regards

Belleg