Usually you build web services that are called by the mobile app in order to perform CRUD operations at the database layer

Dear Frederick!

Using Android as example, the development is usually based on Java. If you are familiar with this language, the process can be easier to you.

More practical details can be found at:

http://code.tutsplus.com/tutorials/android-sdk-app-data--mobile-20680

Best regard,

    Walter Priesnitz Filho

Hi Frederic,

There are many tools aiming to support the back-end needs of mobile applications in the market. You may wish to check Parse, Firebase and Wakanda as examples.

Hope this helps

Baki

One of the most straightforward solution is to build php webservice that extract required data in JSON from the database (if you use linux as a webserver). There are plenty of tutorials all over web, my suggestion is to check andoidhive website.