Retrieve distinct tokens from SQLite3 column

I want to add a new feature to my bookmarking utility, Buku: retrieve all distinct tags.
Buku uses SQLite3.
A bookmark entry can have multiple tags separated by commas (,) in the same column tags.
Instead of retrieving the distinct values from column tags and then parsing them, is there any way I can tokenize the tags by comma and retrieve the distinct tags?

Any help is much appreciated.