Verifying that foreign keys are configured

For subsetting to work correctly, your source database must have foreign keys configured correctly.
Foreign keys are often set up directly within the source database. However, you can also set up virtual foreign keys within Tonic. For example, a foreign key relationship might be missing, or your database might not use foreign keys. If your database uses polymorphic keys, then you must use the foreign key upload to add those keys manually. See Viewing and adding foreign keys.
Without foreign keys, Tonic does not know how to navigate the relationships in your data. Properly configured foreign keys allow Tonic to select the necessary rows from other tables, which ensures referential integrity.
Occasionally, circular dependencies occur in foreign key relationships. For information on circular dependencies and how Tonic handles them, see How Tonic handles circular foreign key dependencies.