Every foreign key — click one to find it on the board.
MySQL has no in-browser engine. Your schema can run on SQLite or PostgreSQL instead — same tables, same keys, each in its own SQL:
Press ▶ Run: the schema is created in a fresh in-memory database, a few rows are added to every table, then your query runs.

Import DDL

Paste CREATE TABLE statements from SQLite, PostgreSQL or MySQL. Primary keys, UNIQUE, NOT NULL, REFERENCES and FOREIGN KEY become cards and lines.