Connect to external database (MySQL) - Using Swift

I'm starting a new project, and so far, every time I connected to a MySQL DB, I used a PHP to retrieve the information and parsed it to JSON, however, I want to know if there are any other methods or resources to do so (like an API, for example). What I would love to do is a way to send a command, for example: select * from ????, directly from the app (as a String), or something alike.