You can now use foreign key constraints in PlanetScale databases, allowing for more flexibility and integrity in your data models without requiring reworking existing applications or frameworks. This feature is available in beta on a per-database level for all unsharded databases, with sharded database support planned for next year. With the introduction of foreign key constraints, developers can now use PlanetScale out of the box with their favorite ORM or framework that uses foreign key constraints by default, without needing to make changes. Additionally, users can import existing MySQL or MariaDB databases with foreign key constraints into PlanetScale using a database import tool, and test the feature with various popular ORMs and frameworks.