HIHello everyone
I have a Raspberry Pi that contain some data,
on another side, I have a server with a server, also there is a webpage connecting with the same server.
what do I need? 
1- the Raspberry Pi must send its data to a server 
2-if the user set some data to the database by webpage the Raspberry Pi must get this data 
3-Raspberry Pi must listen to the database to know if there is an update or not.
what the best way to do these points, is there any protocol for IoT can do these? 
I need any hint :) 
thank u for all.
Try connecting your RPi with your server through any means of local area connection, it could be a connection through a wifi network or using a lan cable or even through serial ports. If successful in this attempt then you can access disk drive folders inside the server. In the webpage running on server ,make it listen for certain values and write the status to a text file or an database. Then make RPi to continuously monitor those file for data updation and make it work according to it.
how set/get data from Raspberry Pi to server