The way to do this is use a REST interface to MS SQL and make ajax calls to query the database.
One option is dreamfactory.com, unfortunately it is no longer free for MS SQL. I use it a lot with MySQL and XDK and works great.
Searching for alternatives, I found sandman2, I don't know it but seems promising:
sandman2 automagically generates a RESTful API service from your existing database, without requiring you to write a line of code. Simply point sandman2 to your database, add salt for seasoning, and voila!, a fully RESTful API service with hypermedia support starts running, ready to accept HTTP requests.
It is python, so you need a server with it.
Sorry for not give you more help, I'm not using MS SQL databases, but these could be the starting point to you for research.