Bidirectional Communication between SharePoint

Question

Hi Folks,
I am pretty new with Sharepoint 2013 development but pretty familiar with SharePoint basic use (such as: creating a list, making a subsite, etc)
So, here is thing. My company that I am interning with is currently having a Database issue of how to manage our employee informations. 
Currently, how our database works is we are having a GIANT-LIST of Access Data table that contain all of employee information. It was managed by the head of our HR (OR Another department). So the
HR manager can navigate through access table to look out for employee information. 
Then, each of those employees have individual Sharepoint subsite. Inside each of these subsites, there are SharePoint List (or something) that contain only their information. 
---------------------THE PROBLEM IS-------------------------
We would like somehow to connect each of these individual employee's lists from their subsite to main database. We are using SharePoint as a end-user interface. Basically, we want to create a CRUD
website using SharePoint2013. But one employee can't look up other employee's information.
I know there are several ways to tackle this issue. I would greatly appreciate it if you come up with any idea with resources of how to actually implement it. (Still newbies with SharePoint
environment). The main thing that bugs me a lot is the communication between the SharePoint and some Database system.
My questions are:
1. We are thinking about making an SharePoint App that will connect SharePoint with Microsoft SQL Azure Database. Is this realistic approach?
2. My partner has created Access Web Database as well. Is there some ways to connect that with SharePoint List etc?
3. Basically the main problem is: I want to make some kinda of CRUD website. So when the employee update the information, it will be updated to the database as well.
4. It can be anything, it's not stuck within SQL Azure Database or Access Web App.
If you do have some solutions, please post the way of how to implement it.
Thank you for your attention, looking forward to hearing from everybody.
Best,
Iskfendi

Answer 1

Yes, It is possible using BCS but you will have to add some customization. But one of the limitations
“Row Level Security”
The point is that while SharePoint 2010 Business Connectivity Service has limitations, it does not mean your implementation should be limited. By understanding surrounding technologies like SQL Server, .Net you can achieve item level security and display
external data as required.
Refer below article to set item level security.
http://www.pdfshareforms.com/business-connectivity-service-with-item-level-security-and-pdf-forms/
http://sharepointpromag.com/sharepoint/6-lessons-developing-business-connectivity-services-solution
Hope this will help you
Senthilrajan Kaliyaperumal