基于PHP的代码用于过滤mysql结果，我可以提高效率吗？

I've made this php code for filtering the results from a mysql database. It works very well, but I'm sure this is not the most efficient way (or proper use of the language) to achieve the desired results. I'm trying my best to get "good" at writing code and would appreciate some feedback on how I could do this better.I've made this php code for filtering the resul