I assume you have a simple home-like network with a router and all the computers behind it and want to build a virtual LAN with Hamachi, where you can safely access your SQL server outside the physical network?
If yes, then the stuff isn't really rocket science.
Here a short simple overview what to do:
a) install the hamachi software on all clients that need access to the SQL server and log them all in with your account
b) log into your logmein website profile and set up a hub-and-spoke network or whatever network type you want.
c) edit your network and add all the clients and hosts on the website
d) restart all devices that has hamachi.
e) now all clients and servers has virtual IPs that you can use