i am an android developer. My boss wants me to work on the backend as well. he wants me to learn how to create web services and also work with databases. What language do i need to learn for that an could anyone provide me with links to good tutorial websites. Thanks.
It's depend upon the platform to platform and purpose of the coding of web service.
For light and faster web service you have to look at new technology Angular JS and PHP.
You can also use .Net, JAVA & Paython to develop web services.