MySQL ORDER SELECT based on a score
To respond to your question, if you want to validate multiple conditions for a case statement, you can use coalesce or nest case statements.

However judging by what you want to do, it might be best to handle this within your application.
SQL Server is not made for computing, it's a database, inherently meant to store and produce data. As such it's been highly optimized for just those types of tasks (storing and handling data) and not for handling the data after it's been found.

Quick edit to link MySQL case nesting after noticing you're talking about MySQL not MSSQL.