To execute them against a database during runtime. I'm a little amused as to the question, I'm certainly not using them as tea coasters.

Edit: and maybe to add more context (and a bit less glib). My approach to interacting with an rdbms is to put each query in a separate SQL file (so no dynamic SQL and no query builders - ORM or otherwise) and execute them with a simple db client. In this case pg-promise. I've landed on this approach after many years of using various approaches and seeing how those approaches take affect on a team/product over time. Though of course ORM vs raw SQL is an argument as old as time (or as old as ORMs at least).