用户在iPhone上为SQLite定义的功能

Question

I'm working on the n'th application locating zip's. Everything works fine in PHP while I worked along the docu on OpenGeoDB. Now, I'm trying the implementation on the iPhone-SDK, but SQLite doesn't have the ACOS, SIN etc funcs. Can anybody point me to an example of how to expand the SQLite with userfunctions in order to use them in a select?

Any hints appreciated!

Thanx and happy coding! Marcus

Answer 1

This one clears it up pretty nicely:

http://www.thismuchiknow.co.uk/?p=71

Answer 2

sqlite3_create_function(database, "yourAwesome", 4, SQLITE_UTF8, NULL, &yourAwesomeFunc, NULL, NULL);