What's the best way to connect iPhone app (iOS SDK) to php/MySql backend

New to iPhone dev here. Just wondering what's the best开发者_Python百科 way to connect an iPhone app frontend (based on Cocoa) to a php/MySql based backend?

The iPhone application will frequently access and change data stored on our server.

Many thanks

You will need to create a web service that will expose a set of APIs that are then use by your iPhone app to push/pull data. You may then choose to cache the data locally (on the iPhone) in a sqlite3 database. The most common data transfer formats are JSON and XML.