dianaf
Uploaded by
9 SLIDES
117 VUES
90LIKES

The Relational Model in Databases

DESCRIPTION

Explore the key concepts of relational databases including keys, integrity constraints, base relations, and views. Learn about entities, domains, tuples, and the importance of data integrity.

1 / 9

Télécharger la présentation

The Relational Model in Databases

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 3 The Relational Model

  2. Agenda • Concept • Property • Key • Integrity Constraint • Base Relation & View

  3. Concept • Relation • Attribute • Domain • Tuple • Degree • Cardinality • Relational Database

  4. Property • Unique relation name • Unique attribute • No duplication tuples • No repeating group (single value for an attribute) • Same domain for an attribute • Insignificance of the tuples or attributes order

  5. Key • Superkey • Candidate key (Alternative key) • Primary key • Foreign key

  6. Integrity Constraint • Null • Integrity constraint • Entity • Reference • Domain (edit or field) • Enterprise (business rule)

  7. Base Relation & View • Base relation • A named relation of an entity in conceptual schema • Tuples stored in physical database • View • Virtual relation • Dynamic generated for end user • Not stored in the physical database • Purpose of views • Security • User friendly report • Performance

  8. Points To Remember • Concept • Property • Key • Integrity Constraint • Base Relation & View

  9. Assignment • Review chapters 1-3, & appendix c • Read Chapter 4 (skip relational calculus 4.2) • Do Exercise 3.8 • Due date:

More Related