1. Define your schema

A schema is the set of tables you want, their columns, and the links between them. There are three ways to start, and you can mix them: load a preset, then add a table by hand, for example.

Your work is saved automatically in this browser. To start over, click Clear in the top-right corner of step 1.

Option A: Start from a preset

Click Retail, Healthcare, Finance or Telecom. The preset is highlighted with a check mark and its linked tables load into the editor below.

Preset	Tables
Retail	customers, sales, support_tickets
Healthcare	patients, appointments (includes long notes and PDF referral letters)
Finance	accounts, transactions (includes JSON metadata)
Telecom	subscribers, usage_records

Presets are the fastest way to see the whole workflow, and a good base to edit into your own schema.

Option B: Draft with AI

1. In the Draft with AI box, describe your domain in a sentence — or click one of the example chips, such as Insurance policies, claims and adjusters.
2. Click Draft schema (or press ⌘/Ctrl + Enter).

In a few seconds the AI drafts 1–4 linked tables and loads them into the editor, along with a Domain context sentence:

Write prompts that name the entities and how they relate. “Hotels, rooms and bookings; each booking belongs to a room and a guest” gets you better links than “hotel data”.

Option C: Import an existing model

Under Or import an existing model, choose one of:

• Upload file — .sql, .ddl, .json, .xml, .csv, .txt, .yaml, .yml, .dbml, .md (up to 2 MB), or an ER-diagram image .png/.jpg/.jpeg/.webp (up to 5 MB). This covers SQL DDL, ER-tool exports (Erwin, Visio, MDM tools), data dictionaries and JSON schemas.
• Photo of a sketch — on a phone this opens the camera. Photograph a whiteboard or paper sketch of your model.

Every import opens a review screen first. It lists each table, the type chosen for each column, the links found, and any sample values:

Check the types before you continue. In the example above, the AI read the hotel name column as Full name (a person’s name); you would change it to AI text in the editor. Then:

• Click Use this schema to load it into the editor, or
• Click Discard to cancel. Nothing changes until you choose.

Good to know:

• Primary keys become ID/UUID columns and foreign keys become links. Original names are kept, in snake_case.
• Include one example row (an INSERT, or a CSV/JSON row) and those values become sample values that generation imitates. In the example, BK-2024-00042 teaches the generator your booking-ID format.
• A JSON file already in DataGenStudio’s schema format loads instantly, without AI.
• If the AI service is unavailable, SQL/DDL and CSV files are still read by a built-in parser. The review screen tells you when this happens.
• Erwin’s native binary files (.erwin) can’t be read directly. Export to XML or SQL from Erwin first, or upload an image of the diagram.

Tips for sketch photos

• Draw one box per table, with the table name at the top and one column name per line inside.
• Draw a line between related tables. Crow’s feet or an arrow on the “many” side tells the AI which table gets the link column.
• Column names drive types: notes or description become long text, attachment or scan becomes a PDF, payload or metadata becomes JSON.
• Neat block lettering on a plain background reads best.

Edit tables and columns

Each table appears as a one-line summary showing its columns and links (customer_id → customers). Click a table to expand it:

For each column you set:

Field	What it does
Column	The column name, as it will appear in your database
Type	What kind of values to generate. See Column types for all 24
Options	Depends on the type: min/max for numbers, a date range, the list of values for an enum, a hint for AI text, or the target table and key for a link (🔗)
Sample value	Optional. Generated values copy its shape, e.g. CUST-000042 → CUST-000001, CUST-000002…

You can also:

• Rename a table in Table name. Links that point to it update automatically.
• Add column at the bottom of a table (up to 20), or remove one with the trash icon.
• Add table below the last table (up to 8), or delete a table with its trash icon.
• Fill in Domain context: one sentence about your data, such as “Online retail store with customers, orders and support”. It helps the AI write values that fit.

The footer shows a running total, e.g. 3 tables · 24 columns · 3 links. If a warning appears under the editor (for example, a link with no target table), fix it before generating.