Entity-Relationship Diagram Skill

Before you write a migration, it pays to see the data model: the entities, their key fields, and how they relate (one-to-many, many-to-many). This skill turns a described domain into a clean Mermaid ER diagram with proper cardinality notation and the attributes that matter.

Required Inputs

Ask for these only if they aren't already provided:

• The entities — the core objects/tables (User, Order, Product…).
• Relationships — how they relate, and the cardinality (a user has many orders, an order has many line items).
• Key attributes — the important fields per entity (especially keys); full column lists aren't required.
• The domain — what the system does, so the model is realistic.

Output Format

[Domain] — data model