If all else fails, social engineering is the place/thing to be!.. go.!..do!
This can be very tedious and its pretty hard to keep up,
but it almost never fails! You can make a very educated guess about what the database tables are,
if you look good enough. I usually start at a login form.
If the user and password fields are named: 'user' and 'password' the database layout will probably be: