How do I learn CodeQL and run queries?
There is extensive documentation on getting started with writing CodeQL. You can use the interactive query console on LGTM.com or the CodeQL for Visual Studio Code extension to try out your queries on any open source project that's currently being analyzed.
We welcome contributions to our standard library and standard checks. Do you have an idea for a new check, or how to improve an existing query? Then please go ahead and open a pull request! Before you do, though, please take the time to read our contributing guidelines. You can also consult our style guides to learn how to format your code for consistency and clarity, how to write query metadata, and how to write query help documentation for your query.