WDB files are used in Windows Work Database, and since they are discontinued, you need to use one of these methods to open WDB files ...

Open the Files app. In the left navigation panel, choose the drive containing the file. Find the file in its folder, then double-click to open it. Alternatively, right-click the file and select Open.

A co-worker or colleague has shared folders and files with you from their Microsoft OneDrive storage. Now you have to determine the best way to access those shared items.