Relational Model Fundamentals
The chapter delves into the fundamentals of the Relational Model, outlining its critical components such as relations, attributes, tuples, and domains. It elaborates on essential characteristics and keys that ensure data integrity, including primary keys, foreign keys, and unique keys. Furthermore, it introduces the concepts of integrity constraints and mathematical frameworks like Relational Algebra and Relational Calculus, which underpin SQL and database operations.
Sections
Navigate through the learning materials and practice exercises.
What we have learnt
- The Relational Model represents data in structured tables called relations, consisting of rows (tuples) and columns (attributes).
- Keys are crucial for uniquely identifying records and defining relationships between tables, including primary keys, foreign keys, and unique keys.
- Integrity constraints such as domain, entity integrity, and referential integrity enforce rules that maintain data accuracy and consistency.
Key Concepts
- -- Relation
- A two-dimensional table in the database, consisting of rows and columns where each table has a unique name.
- -- Attribute
- A named column in a table that describes a specific characteristic of the entity represented by the table.
- -- Tuple
- A single row in a table that represents one complete record or instance of the entity.
- -- Domain
- The complete collection of all valid values that can be assigned to an attribute, setting rules for data types and formats.
- -- Primary Key
- A special candidate key chosen to uniquely identify each row in a table, must never contain NULL values.
- -- Foreign Key
- An attribute in one table that refers to the primary key in another table, establishing relationships between the two tables.
- -- Integrity Constraints
- Rules that ensure the accuracy and consistency of data in the database, including domain, entity integrity, and referential integrity.
- -- Relational Algebra
- A procedural query language used to describe how to retrieve specific information from relational databases.
- -- Relational Calculus
- A non-procedural declarative query language that allows stating what data to retrieve based on properties without specifying steps.
Additional Learning Materials
Supplementary resources to enhance your learning experience.