but i dont know how to sent data from arduino to database server.
The Arduino as EthernetClient example illustrates that.
Sending data to a server involves making a GET request (or a POST request, but the GET is conceptually easier).
After the name of the script to execute on the server, put a ? followed by name=value, where name is a name that the script expects, and value is the value you want to send. It you want to send multiple values, use & and name=value for the second and subsequent data.
GET /someScript..php HTTP/1.1 <--- Get some web page from the server
GET /someScript.php?temp=37 HTTP/1.1 <--- Have it store the temperature
GET /someScript.php?temp=37&humid=98 HTTP/1.1 <--- Damn, it's hot and muggy