how to read data from external connected device and store it to thingworx database

Hello 

how to read data from external connected device and store it to thingworx database, and how the changes are reflected. I don't have any connected devices but I am assuming that it is connected , now i want to know how i will map the data coming from my real device to the 'Thing' that I created in thingworx. 

And then store that data to database.