You can find utilities like Exportizer that allows users to explore databases (.db) and export them for example as formatted text files, typically with field separators or fixed length fields. Should perhaps be also possible with any database management programs with capabilities to export to CSV format, which is basically specially formatted text file.
Convert Database file to Text file.
We found one software available in the database for this conversion.
Microsoft Windows software - convert db to text on Windows
A database exporter
Convert from db file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.