Data, Backup & Sync

Where your data lives and how it moves. A business keeps one master database (business, users, settings) and one detail database per financial year. In Local DB mode that is a file on the device; on a Local Server it is on the server (SQLite or SQL Server); in cloud mode it is the SKS service. Devices sync through the server; backups are files you keep.

Where it is in the app

Settings > Data Manager, Settings > Financial Years, Server Admin from the login screen (Windows local server), Tools > Switch to Server / Switch to Local, the Sync button on the POS page, and the Local Setup / Server Admin tools.

Topology

flowchart TD
    subgraph Cloud["Internet mode"]
        A1[Device] <--> C[(SKS cloud service)]
        A2[Device] <--> C
        B[Buyer app · online store] <--> C
    end
    subgraph LAN["Local Server mode"]
        S[(Server: Windows service or SKS Server app
SQLite per year or SQL Server)]
        D1[Counter 1] <--> S
        D2[Counter 2 / phone] <--> S
        W[Waiter app · KDS] <--> S
        S -.->|optional online sync| C
    end
    subgraph Solo["Local DB mode"]
        L[(One device · SQLite file per year)]
        L -->|Switch to Server| S
    end
    S & L --> BK[Backup file · restore · export]

Pick the mode per device at first run; a solo device can graduate to a server later.

Tasks

Backup - Data Manager writes a backup of the master and the current year (and can schedule it); keep it off the device (drive, cloud folder). Restore from the same screen.
Financial years - create the next year before the old one ends (the dashboard banner reminds you); opening balances carry forward; switch between years to see history.
Sync - devices connected to a server sync continuously; the Sync button forces a pass and shows the last sync per table. Deleted rows are tracked so every device removes them.
Local server setup - install the Windows service or the SKS Server Android app, then point counters at it (found automatically on the LAN, or by IP / QR).
Switch to Server / Switch to Local - move a Local DB device onto a server it has been activated for, or let a server client keep working locally when the server is down.
SQL Server - Advanced mode on a Windows server keeps each year in a SQL Server database; chosen when the first business is created, and changeable from Server Admin.
Migrations - the app upgrades the database schema itself on first open after an update; a fresh year starts on the current model.

When something goes wrong

flowchart TD
    A[Trouble] --> B{What kind?}
    B -->|server not reachable| C[Counters keep working locally where allowed]
    C --> D[Fix the server or the network]
    D --> E[Sync catches up automatically]
    B -->|a device is behind| F[Force a sync · check last sync per table]
    B -->|year is ending| G[Create the next financial year early]
    G --> H[Balances carry forward]
    B -->|data lost or device dead| I{Recent backup?}
    I -->|yes| J[Restore it · re-enter the gap]
    I -->|no| K[Only what synced elsewhere survives]
    K --> L[Set a backup routine now]
    E & F & H & J --> M[Back to normal]

The branch that ends badly is the one with no backup — every other problem here is recoverable.

Good practice

Back up before an update and at least weekly; copy the file off the machine.
Create the next financial year a few days early.
On a LAN server, give the server PC a fixed IP and keep it on a UPS.