i want to use fmdb in my iPhone application. What are the differences in using sqlite with fmdb without fmdb?
i need to be able to write queries.
how the fmdb is easier/effecient to use than single sqlite? if there is any source code or guide to it please post its link
FMDB is a wrapper on top of SQLite's C API with an API more in Objective-C style. Which API style is "easier" is more up to you, it would depend greatly on your programming background and personal preference.
There's a guide showing how to use FMDB at its GitHub page which shows the API off pretty well, you should definitely read that before deciding.