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Show HN: DDL to Data – Generate realistic test data from SQL schemas

55 points by tbrannan ↗ HN
I built DDL to Data after repeatedly pushing back on "just use production data and mask it" requests. Teams needed populated databases for testing, but pulling prod meant security reviews, PII scrubbing, and DevOps tickets. Hand-written seed scripts were the alternative slow, fragile, and out of sync the moment schemas changed.

Paste your CREATE TABLE statements, get realistic test data back. It parses your schema, preserves foreign key relationships, and generates data that looks real, emails look like emails, timestamps are reasonable, uniqueness constraints are honored.

No setup, no config. Works with PostgreSQL and MySQL.

https://ddltodata.com

Would love feedback from anyone who deals with test data or staging environments. What's missing?

12 comments

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ForHackernews
This is a great idea. I've thought about doing something similar! On the other hand, I'm not sure it's a business. Is this using AI?

The pricing seems extremely high for what's basically a call to https://github.com/faker-ruby/faker but that makes sense if it has to pay for OpenAI tokens.

(who knows though, plenty of B2B deals signed for sillier things than this - good luck, OP)

james_marks
Congrats on being launchable!

I've written seed data scripts a number of times, so I get the need. How do you think about creating larger amounts of data?

E.g., I'm building a statistical product where the seed data needs to be 1M rows; performance differences between implementations start to matter.

bdcravens
I appreciate this product existing, but the row limits in each tier seem very constrained.
ljm
Reminds me a bit of Snaplet before it embarked on its incredible journey to get acquired by Supabase and shut down.

I like the concept but the painpoint has never been around creating realistic looking emails and such like, but creating data that is realistic in terms of the business domain and in terms of volume.

dmarwicke
does it handle skewed distributions? faker's always been useless for this - like, your test data ends up with everyone having 5 orders when real data is all long tail
NDizzle
SQL Server support would certainly help you sell enterprise plans.
Antitoxic6185
I have something that gives you the data in CSV/SQL insert statements.

I also provide an option to select how to generate data for specific fields.

https://fakemydb.alles-tools.com

UI is a bit clunky - will revamp it :)

gerardnico
Real Test data génération as saas was not a viable business for us.

Developers use their tool or develop a script (with ai or not)

We made it free, the value comes when you can use it in your development process.

https://www.tabulify.com/learning-tabulify-step-9-how-to-fil...

The cost of calling a service is also not free.

In all case, all the best in your endeavour.

mikhSh
hey tbrannan, nice tool! i was actually comparing a few of these recently for the staging DB and ended up trying https://seedfa.st/ since i needed something that works in CI pipelines(we use github actions). the main difference i actually noticed is that ddl-to-data is web-based and seedfast is os-native(because its actually a cli tool first) and integrates with CI/CD pipelines smoothly. both handle FK constraints fine, but tbh i prefer not having to copy-paste schemas into a web UI every time. though your pricing looks much more straightforward for small projects which i like more