Question

I am developing a cocoa application that will be making heavy use of both web services and a standard dbms (most likely MySQL) and I am wondering if anyone has a good option for a database library or ORM solution they have used. CoreData is not an option due to the need to support a standard DBMS and to be able to modify the data outside of the normal application operation.

I have found a number of possible options from new open source libraries: http://github.com/aptiva/activerecord/tree/master

To writing my own wrapper for the C MySQL api.

Any advice is welcome,

Thanks!

Paul

Answer 1

We faced a similar question when we first started work on Checkout, our solution was to code the entire app in Python, using PyObjC.  Checkout 1 had an sqlite backend, Checkout 2 has a postgres backend.

There are a couple of really mature and powerful ORMs on the Pyton side, such as SQLObject, which is pretty simple to work with (we used it for Checkout 1.0) and SQLAlchemy, which is more powerful but a bit harder to wrap your brain around (we used it for Checkout 2.0).

One approach you could evaluate, is building the application in Objective-C, but writing the data model and database connectivity/adminstration code in Python. You can use PyObjC to create a plugin bundle from this code, that you then load into your app  That’s more or less the approach we took for Checkout Server, which uses a Foundation command-line tool to administer a postgres server and the databases in it, this CLI tool in turn loads in a Python plugin bundle that has all of the actual database code in it.  End-users mostly interact with the database through a System Preferences pane, that has no clue what the database looks like, but instead uses the command-line tool to interact with it.

Loading a plugin is simple:

NSBundle *pluginBundle = [NSBundle bundleWithPath:pluginPath]; [pluginBundle load]; 

You will probably need to create .h files for the classes in your bundle that you want to have access to from your Obj-C code.