DetStartups

I'm trying to set up an ideally "no- code" way to have a backend of 3 different tables and be able to find a value in table #3 (contains businesses & cities) by first finding a record in table #1 (7,000+ zip codes) that corresponds to a city (table #2 has the unique cities), and then finding which businesses are located in these cities ( in this specific, original zipcode lookup). And return the business and a description via an API to a front-end results page, which happens to be a WordPress page - but doesn't need to be. I've tried Airtable's API, AirPress (a finicky WordPress plugin for Airtable's API), and I've looked at Sheetsu and a similar spreadsheet as backend and a simple API. I run into the issue where they work fine when you just need to query 1 table, but when you need to use the result from that query in another query to a different table. I'm back in SQL land - where sure it could be done with SQLite - needing to probably create an intersection table or a JOIN and build an API off of that. Is there a way to accomplish what I want without going back to SQL queries and some API?