What mobile framework is suitable for a project which requires frequent database communication?

I have been struggling between jqtouch, iphone sdk and sencha touch for the past week. I still cannot make up my mind which is the most suitable mobile framework for my project. My project need users to submit content based on their current geological lo开发者_开发百科cation, thus often fetching and submitting data into the database. It's abit like foursquare. I'm skilled in html, css, jquery and vanilla javascript.

Experts of SO please advise me~

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If you don't need the speed of native code, I wouldn't bother writing the app in Object C unless you are very comfortable with it. JQTouch is great for those who are comfortable with html, css, jquery and javascript, however it will bog down on older iPhones (pre 3GS) if you have more than 4 or 5 screens. Sencha has a lot steeper learning curve, and costs money to License (they just released the commercial licence costs and it is very reasonable at $99 dollars a seat) and would probably be more comfortable to those with more of a programing bent. But for the database access, if you are going the embedded html page route, it is really all the same -- make an api of a bunch of rest JSON calls and you will be fine. Since it is submitting to a database, you can do everything async without worrying about it, now the question is what database backend to use for a mostly write database...