One of the best ways to ensure you have another up-to-date copy of your Codebook data is to make use of the Sync feature. If you are using Codebook on iOS or Android, pick up a copy of Codebook for Windows or Codebook for OS X get your data synced over to your desktop.
Codebook on the desktop is sold separately, and not everybody has the option of syncing with the desktop over WiFi, or another device to sync with. In these cases we recommend that you at least sync with a Google Drive or Dropbox account, which will store an encrypted replica of your data in the cloud service. Should you need to install Codebook fresh for whatever reason, you’ll be able to do a restore sync to bring your data right back.
If you are using Codebook on an iOS device, you have the option of backing up your whole device to iTunes or iCloud. iCloud backup is a particularly convenient means, as your device can be regularly backed up overnight while connected to WiFi. Apple has good instructions available for backing up and restoring iOS devices, along with a guide on how to choose between iTunes and iCloud for backup.
If you are using Codebook on Windows and OS X and have ever used the sync feature there, Codebook will have saved a backup copy of your database from right before the sync operation. You can review these in the Backups view under the File menu and select one to revert. Instructions for manually installing one of these files to restore your data are available.