AQA NEA Computing - URGENT !!!

I have created a database system where the user and admins can login and register as well as some forms that can be filled in and sent to the database. I have about 5 tables where 2 are interlinked. I have made pages where the user can view some tables. I have used PHP, Javascript to create scientific mathematical functions and for page functions, queues and small hashing for some pages.
Since my system uses SQL what would i need to do to get more marks? Do I need to just join tables or would SQL commands like CONCAT, ORDER BY be ok as I have used these? I also don’t have any mathsy things in my database so what would be suggest tables to make for that so that I can use AVG, MIN, MAX, SUM and COUNT.
What would I need to make my project more complex to get more marks in the technical solution? When I look through the list of technical skills it talks about reading and writing files, OOP model, searching, sorting, data structures. Can these skills be added to a database system?
Even if it’s just general things that could be added to the project. It would be much appreciated.