在Windows Phone上处理SQLite聚合函数的结果

I'm working on an app (SleepTracker) and I'm trying to put together a statistic feature based on data saved in a SQLite database using different aggregate functions. What I'm trying to achieve is to query the table with an aggregate function that I've wrote already, and store the result in a string that is bound to a textblock on the View.I'm working on an app (SleepTracker) and I'm tr