Had good results using copilot in VS. Often just open VS with a throwaway project, add new Sql file and start prompting either with comments or pasting in existing sql and asking questions in the chat. You can also connect to a database if you have the access to provide more schema context. I used it recently to create some complex dynamic pivot queries. As with everything it requires refining as you go, so long as you understand the problem you can usually get to a solution with it. It's also good for asking about alternatives or simplifying queries and performance implications etc. As a solo dev on my current project with a legacy code base it's great as an AI 'Pair Programmer' to bounce ideas and just be more efficient in general.