SQL Server 2008: How do I deploy changes?

I have a SQL Server and a live database that is used in a .Net application. I want to make changes to the tables on this database without losing the data. What is the best way of deploying these changes? SQL Scripts may be one way, but although they can be tested beforehand I do wonder开发者_开发技巧 if they are risky as well. I am sure there are lots of links that can help me here but I am not Googling the right words it would seem.

I deploy using scripts. When my changes involve table/data changes I will make a copy of the destination database and test my deployment to that first. After all the bugs are worked out, then I can deploy live.

Yes, there can always be risks, but at some point you must decide that you have tested enough and move.