i want to make device as web & mysql server with ardunio. whether this is possible using the Arduino
The Arduino with ethernet shield can talk to a web server where MySQL is running.
The Arduino can not be a MySQL server. There is no download available for the Arduino.
I was once looking for a way to interact with a MySQL server directly, bypassing the webserver... but the encryption makes it impossible to achieve.
However, here's a document explaining how to do it.