What does HackerNews think of automatic-api?
A list of software that turns your database into a REST/GraphQL API
This list might be of interest for your friend, however I have no idea how good or bad these solutions are :
https://github.com/dbohdan/automatic-api
The most lazy way would be to use CouchDB. However when you have no schema in your database (NoSQL) you have to implement it (poorly) in your application. Relationnal DB are harder at first but end up a good long term investment imo.
Added: This type of software lacks a standard name and an established "format" (like HTTP servers or word processors have a "format"), so it is hard to discover other projects even when you are aware of a few. I've taken to calling them "automatic API servers" and promoted the term a bit. Some projects have adopted the GitHub topic "automatic-api" (https://github.com/topics/automatic-api) as a result. My hope is that a name and a search tag will help with discovery and make it more of a distinct type of product.