[Skunkworks] How to make an advanced search in php mysql

Hallo Guys, I am implementing a n online job application and in the back end I need a search criteria i= to search applicants by Position applied, Search by qualification e'g drop down with Bsc Comp science etc, and search by age which right now does even appear feasible to me as i have a field called date of birth of course we cant put age in the db Any suggestion link sample code will do me a lot of good Regards and Merry Xmass and a happy new year