Devin Walters (devn) has created the nifty codeq-playground, billed as:
A quick and easy way to play around with queries against your Clojure Git repositories. ... codeq-playground includes a few examples of what you can do with Codeq. They’re stolen liberally from the Codeq blog post and from Rich Hickey’s unsession talk on Codeq at Clojure/conj 2012
The examples (in the codeq-playground core.clj) look very useful (if largely undocumented). Basically, they contain Clojure-based queries and rules for use with Codeq. With this as inspiration, I have created this "Codeq Cookbook".
I have edited query examples from codeq-playground into wiki pages, adding information about caveats, idioms, motivation, use, etc. Each page is formatted as a standardized set of sections (reminiscent of Unix man pages). The content mimics that of assorted "Foo Cookbook" volumes.
This cookbook concentrates on Codeq-specific recipes. For Datomic-specific recipes, see datomic-cookbook.