What is the best way to track new changes in call log?

I need to store call log into a local DB, so I will insert call log first, then I want to track all new calls. So should I use Broadcast or ContentObserver ?

another question how to insert data form cursor without looping for example I want to insert four columns in the following cursor

Cursor managedCursor = managedQuery(CallLog.Calls.CONTENT_URI, null,
null, null, strOrder);
int number = managedCursor.getColumnIndex(CallLog.Calls.NUMBER);
int type = managedCursor.getColumnIndex(CallLog.Calls.TYPE);
int date = managedCursor.getColumnIndex(CallLog.Calls.DATE);
int duration = managedCursor.getColumnIndex(CallLog.Calls.DURATION);

How to insert these columns as a strings without looping