Squint your eyes a lot! A GraphQL query is just a query on some objects having some fields. You can tie any function to a field. In particular, you can have ea

Squint your eyes a lot! A GraphQL query is just a query on some objects having some fields. You can tie any function to a field. In particular, you can have each field be a function which executes SQL code. And that code is free to JOIN as it wants. Squint your eyes some more: how do you do it in a RESTful interface? It is the same idea. GraphQL really excels, however, in that it is not tied to SQL. You can have part of the query be from one source, and other parts be from other sources.