I work with SQL Server at work and MySQL occasionally at home. Right now, I'm working on creating a library for C# to load the data and easily access it via LINQ. After I'm done with that, the plan is to write some scripts to load the data from the CSVs into a database.
If you are going to be learning anything, I'd think you'd want to learn SQL, although, it would probably take you a bit of time to get to the point that you would be able to produce the data you wanted using SQL.