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 ...

GDB files may be opened with newer versions of the software. Embarcadero InterBase is a database application that is relatively inexpensive compared to other proprietary database products.

In order to open the file, you need a compatible database program. You can use a free SQL database program called Pervasive PSQL to view SDF files.