It seems you're mixing up some things.
A web service is simply some code on the internet (web) which allows you to receive and send information to a server, where it is saved per example in a database.
PHP is just a language, in which you can write a web service.
You can use a vast array of languages to create a web service ( read: expose your database) to other devices. Among others, you can easily do this in Java, .NET, Python ...
If you're looking for a way to connect to an external database without any web service / API in between, i'll have to disappoint you with the news that this is not supported by Android.
Most examples of a simple web service / a bunch of scripts contain PHP since this is probably the easiest and can be used on pretty much any server.