Comment by SkyMarshal

You're more likely to need and use the DB course topics earlier in your career, unless you specifically get a job in ML or AI. However, those topics are also easier to learn and understand on your own without guidance. If you post your school's db course curriculum, we can help you compare it with the Stanford one. Initial instinct - go with the ai or ml course (or take a reduced course load this fall and take both, then see if you can get the Stanford completion certificate to transfer as credits to your school).