database - How to make client PC work independently from Server -

database - How to make client PC work independently from Server -

(sorry, don't know should inquire question here in stackoverflow or other related sites. please move if isn't appropriate)

there unrelated groups of students each grouping members produce info together. each fellow member utilize credentials login client desktop application , send info server. other grouping members should see new info if login credentials.

the problem comes in when want create client works although there error in connection server. don't want stop them if couldn't connect server, create info , later send server.

here problem, without connecting server, how can create memberships in client , sure belongs group, or how can know other fellow member has new info in local machine collegues can see it?

i don't want utilize local server, remote server , local machine database.

if server unavailable, way know if person in grouping if have info stored on client. of course, removed grouping , (disconnected) client not know it.

solving depend on how scheme used.

if membership not alter often, utilize client-saved membership long not old (e.g. utilize if less 4 hours old, or such rule). whenever client re-connects server, should ensure local info refreshed if older n-hours in addition, when connection re-established, , info sent server, server should check 1 time more. if user has been removed group, server can reject data

database security design-patterns web-applications database-design