MySQL + SQL · Lesson 13
RDBMS Concepts with Examples
Core RDBMS Concepts
RDBMS is built on a few core concepts: relation, tuple, attribute, domain, keys and integrity rules.
The Concepts
| Concept | Meaning |
|---|---|
| Relation | A table |
| Tuple | A row |
| Attribute | A column |
| Domain | Allowed values for a column |
| Primary key | Uniquely identifies a row |
| Foreign key | Links to another table |
Integrity Rules
- Entity integrity: primary key cannot be NULL.
- Referential integrity: a foreign key must match an existing primary key (or be NULL).
Summary
- Relation, tuple, attribute, domain, keys form the relational model.
- Entity and referential integrity keep data valid.