GenerateRealData logoGenerateRealData
Home › Use cases › Data Quality & Anomalies
Data-quality & anomaly testing

Bad data, on purpose.

Test validation rules, data contracts and pipelines against the problems real data has: missing values, malformed emails, impossible dates, outliers and duplicate keys.

Free trial for every new account. No credit card.

Orders with injected anomalies: example spreadsheet in a Mac window (orders_dq_test.xlsx)
The example

Orders with injected anomalies

What to look for in the screenshot above. These are the details that usually break in hand-made or random test data.

What you get

01

Choose the anomaly rate

From 1% to 50% of rows; the rest stay perfectly consistent.

02

Realistic defect types

Nulls, formatting errors, outliers, impossible dates, broken totals and duplicates.

03

Loadable when you need it

For SQL output, defects stay within what the database accepts, so the file still loads.

04

Repeatable

Use a seed to get exactly the same dataset, and the same defects, every time.

How it works

From idea to dataset in three steps

1

Describe or upload

Describe your data in plain English, or upload your SQL schema for PostgreSQL, MySQL / MariaDB, SQL Server and SQLite.

2

Review the plan

Check the tables, columns and rules the AI proposes, and adjust anything you like.

3

Generate and download

Choose how many rows you need and download a ready-to-run SQL script, CSV, Excel (one sheet per table) or JSON.

Questions

Can keys and relationships stay valid?

Yes. Columns that other rows depend on, like primary and foreign keys, are protected unless you ask otherwise.

Can I test great-expectations or dbt tests with this?

Yes. The defects are typical of real pipelines, which makes them good fixtures for data tests.

Does AI-written text get damaged too?

No. Anomalies are applied after the text is written, so the AI never writes about a damaged value.

Build your own version of this example

Describe your tables or upload your schema. The free trial needs no credit card.

Start free
More use cases
Multi-Table Relational Data Test Data from SQL Schema User Journeys & Behaviour AI-Written Text Fields ML Training Data Load & Performance Testing Demand Forecasting Geospatial & GPS Tracking Fraud & Transaction Data All capabilities