Finally, i got the simple solution in my case. what I've done is just
install SQL SERVER 2012 EXPRESS
open the SQL SERVER CONFIGURATION MANAGER
go to SQL SERVER NETWORK CONFIGURATION on the left panel
expand it and select the protocol for particular SERVER
on the right panel, enable the TCP/IP
restart the corresponding server
after these steps, all done.
since some of the SQL SERVER setting would disable the TCP/IP by default.
so even when we install Visual Studio, we still couldn't ensure the server is able to be used.
Then what we have to do is to download and Install SQL Server Express at least in order to get the configuration tool.
Honestly this is my first time encountering this kind of problem which is all because of Visual Studio 2012.
hopefully this could help those who have the same problem.