ER Diagram Generator

How it works

• Everything runs client-side — no network request, no upload, no server round-trip.
• Parses standard CREATE TABLE syntax: inline PRIMARY KEY and REFERENCES other(col) on a column, plus table-level PRIMARY KEY (...) and FOREIGN KEY (...) REFERENCES other(...) constraints. ALTER TABLE ... ADD CONSTRAINT statements aren't parsed — declare foreign keys inside the CREATE TABLE itself.
• With "Infer relationships" on, any column ending in _id whose prefix matches another pasted table's name (singular or plural) gets a dashed inferred relationship line — useful for warehouse/dbt schemas that rarely declare real foreign key constraints. Explicit REFERENCES always wins over an inferred guess for the same column.
• Layout is a simple auto-generated grid, and relationship lines are drawn as direct elbow connectors — they don't route around other tables, so dense schemas with many crossing relationships may look busy. Good for a quick structural overview, not a substitute for a dedicated modeling tool on large schemas.
• If a REFERENCES points at a table that wasn't included in your paste, that relationship is listed as unresolved in the status line instead of being silently dropped.