Ionic push notification that triggers when something has changed in mySQL database

Hi, everyone! Can you all please help me. I’m new to Ionic and I’m currently developing an app that has queueing. One feature of my app is that it will notify the user if he’s close to the queue already or if where he is in the queue. I really don’t know how to do this. My database is mySQL. Any resources would be very helpful. If you can give me an example, the better. Thank you so much!