How to update value inside boltDB

I have a user whos age 21 i want to update his age to be 25

Wait 4 years. It will happen from alone.

Aside of that, you really shouldn’t store age in a database of any kind, save the date/month/year of birth and calculate the rough age based on that.

Last but not least, I’m not using boltDB, but I think you could use the DB.Update.