As already Sergey has mentioned that it is not a good approach to communicate with database through AngularJS,
1. AngularJS is client-side. So you would have to bring the database to be offline too, or at least a few tables that are required.
2. Although JavaScript can be used to perform certain actions. But it will make things much more confusing and complex.
In my opinion, what I believe to be done is to communicate with the database using the server-side ASP.NET interfaces only. However, there is still a chance that you will be able to communicate with those "ASP.NET interfaces" using AngularJS. It would be then the interfaces that actually perform the task but you will however be working in the AngularJS only and sending the data to the ASP.NET to store the in database.
Read the following threads to get an overview of performing HTTP requests using AngularJS.
AngularJs $http.post() does not send data - Stack Overflow[
^]
AngularJS Ajax[
^]