Keys and Integrity Constraints
Relation, tuple, attribute, domain, degree and cardinality; superkey, candidate key, primary key, alternate key and foreign key, with prime attributes and superkey counting by inclusion-exclusion; the domain, NOT NULL, entity, key, referential and CHECK constraints; which of insert, delete and update can violate each one; the referential actions CASCADE, SET NULL, SET DEFAULT, RESTRICT and NO ACTION, with a cascade chain run in SQLite; and how CHECK and UNIQUE treat NULL.