This is my first time asking something on this awesome website, so please, be polite with me if I'm breaking some rule.
So, here's my problem, I have developed a e-commerce software for a certain customer, in Asp.NET, MVC4. Then, I developed another e-commerce for a different customer, obviously starting from the last one. Now I have two similar e-commerce projects, differing only for some feature I had to add for the newer customer. The problem is that now, the old customer, wants me to update his e-commerce as well, adding the new features I already added for the other one; of course he doesn't want his data to be lost, so I have to migrate all the data stored in the old database, to an updated version, with a different scheme: for example, the new scheme has tables, relations and columns, not present on the old one.
Which is the best solution you suggest me to follow? Are there functions in sql server already, suitable for the purpose? Does the framework include some solution for this? Thanks in advance, and sorry for my poor english. If I have not explained correctly, I will be happy to give you more detail.