Thoughts / Experiences on SQL as an API

I have seen several examples in the past of SQL being used as an API to access systems or data in more or less powerful ways.

for example :

--- YQL - https://en.wikipedia.org/wiki/Yahoo!_Query_Language

YQL enabled to access web data and some APIs as one big virtual database. eg: "select title, link from rss where url = 'https://www.engadget.com/rss.xml';"

--- osquery - https://osquery.io/

osquery - Query your devices like a database with currently 258 tables implemented (https://osquery.io/schema/) eg: "SELECT name, path, pid FROM processes WHERE on_disk = 0;",

Do you know other similar projects that add an SQL facade on systems, datas or APIs in unexpected ways ? Do you consider that these kind of APIs are fragile or elegant ?

I tried to find a list/documentation of all the endpoints that used to be available in YQL but did not find anything that looked comprehensive to better understand the scope that it used to have. If you happen to know where to find such a list or remember some of the endpoints, I am interested.

Thanks for your time !