Ask HN: I want to build my own query language

[bewal416]

Our product is starting to get more and more requests for custom reports. I’ve built some basic tables with filters and exports to Excel/PDF, but they fall short of the nuance our customers need, especially those in regulated markets.

One customer needs full first names but only the first letter of the last name. Another needs a very specific JOIN with an entity almost no other customer cares about. To accommodate, I’ve been building custom Looker reports for each customer, which won't scale well.

I started looking into how other SaaS companies solved this. Many built their own SQL-like query languages:

- Salesforce -> SOQL - Shopify -> ShopifyQL - Stripe -> Sigma

All of them seemed to address the same problem I’m seeing: customers have unique reporting needs that no-code GUIs can’t handle. A drag and drop builder is great for non-techies, but most real requests require joins and transformations, and I’m trying to avoid becoming a consulting shop for every customer.

I'm particularly impressed by Stripe Sigma because of how they combine SQL with an LLM layer. Users can ask for a report in plain English, customize it in a lightweight BI tool, and edit the query only whenever needed.

Has anyone gone through this or have advice on alternative approaches? I’m open to any direction here.

[doctorzook]

Unless your data is really unusual, I’d generally recommend that you avoid writing your own query language and processor: it’s just damn hard to make it work well. Instead, look at how to put something like DuckDB in front of your data so people can just write SQL.

[PaulHoule]

Or a step up from that: build a compiler that converts queries in a human-friendly or application-specific language to SQL or something similar.

[benoau]

I'd stick with SQL, they can pull queries straight out of ChatGPT if they don't know it themselves.

If everyone lives within one database I'd throw up a per-customer read-only database in front of it for running their queries so they don't create performance issues.

[bewal416]

We do have a single-tenant DB. That’s one of my architecture challenges- how to handle permissions and clean up the schema a bit to entities that only my users need.