4. Client upgrades and uninstallation

4.1. Upgrading the client

Just install a newer version. For example:

  • For Android, install a newer version from the Google Play Store.

  • For Windows, download the newer version and run its installer.

This will replace the CamCOPS software but should find your old (client) databases, upgrade them if necessary, and continue working with them.


It shouldn’t be critical, but as a matter of good practice, move all your data to your CamCOPS server before upgrading the client.


If your client and your institution’s server are upgraded to support new CamCOPS tasks, you should tell the client to check in with the server to retrieve any new strings (etc.) that it might need. Re-register with the server.


Implement a simpler way to do this, without the need to re-register (which requires elevated privilege),

4.2. Where does the client store my data?

The CamCOPS client uses two encrypted databases called camcops_data.sqlite and camcops_sys.sqlite, stored in the device’s user-specific private area, as below. (Note that some operating systems, such as Android and iOS, are designed for single-user use and don’t have the concept of a per-user private area.) For more details, see Client SQLCipher databases.

Operating system

Typical location

Windows 10






The client will tell you the location itself; see Help ‣ View device ID and database details.

On some operating systems, you can specify a non-standard location for the client databases. See Specifying a non-standard database location.

4.3. Uninstalling the client

Use your operating system’s uninstallation process. For example, in Windows, use “Add or remove programs”. In Android, remove the app. But see below!

4.4. Could data be lost if I uninstall the CamCOPS client?

  • Android. Yes! All application data is typically deleted when an application is removed.

  • Windows, Linux. It shouldn’t be. The installer doesn’t touch the data. If you uninstall CamCOPS, the data should be left behind. If you install a new version, it should pick up the old data.


Ensure you’ve moved all your data to your CamCOPS server before you uninstall the client!

4.5. Could data be lost if I downgrade the CamCOPS client?


CamCOPS doesn’t delete unexpected database tables, but it does reshape existing tables. Suppose we have the following situation:

Table, column

Present in old version?

Present in new version?










When you upgrade from the old version to the new version, the new version will add column column2 to table table1, and it will create table table2. You might add data to those tables/columns. If you then manage to install the old version, the old version will ignore table2 (and leave it intact) but it will notice that column2 doesn’t belong in table1 and will delete it – which might lose data.


Avoid downgrading the CamCOPS client. If you must downgrade, be sure to move all your data to your server first!