How I can get my WhatsApp database key on my Classic?

i need to see with whatsapp viewer or sqllite the database of my messages. on the blackberry version of whatsapp i can handle more than 650,000 messages but i backup and restore all this messages to the apk version which is running on my bb10 but crash so often for all the data. if i can read the messages from the data base i will clear all the conversations on the apk version to have it with the minimum data usage possible.

thanks

With that many messages you'd be better off buying a cheap Anroid device if you insist on using BB10 still, sorting out the messages and then exporting your new backup.. that or just borrow someone you trusts Android phone to do it.