The dominant standard, the relational model now often more or less synonymous with SQL, is 45 years old, the first »modern« database systems are more than 50 years old like IDS [1] released in 1964. But even those are usually referred to as 3rd generation systems with a decade or so of development on their back. And if you want to you could go even further back, at least as far as 1884, 130 years, and the Hollerith machines which are at the roots of IBM.
And with this expectation I looked at your project and found something that is probably the most convoluted ways to implement an database that I have seen. Really, don't take it personal, but there is not much that resembles a usual database system design and there is nothing where I honestly could have said that it is a nice idea but it could be improved by doing this or that. I could have suggested to read the Wikipedia article on databases [2] and work from there, but would this really have sounded less rude?