dbms (database management system )1.pptx

pptx for Dbms

1. Introduction to database design, components of dbms Name:- A.manish Roll:-227R1A0504 Sec:-CSE A

2. Database design :- The database design process consists of a number of steps. The general aim of a database design process is to develop an efficient, high quality database that meets For complete DBMS the needs and demands of the application and business stakeholders. The database design process can usually be broken down into six phases, as listed below:

3. Entity :- An entity is referred to as an object or thing that exists in the real world. For example, customer, car, pen, etc. Entities are represented by “rectangle” There are two types of entities. Strong Entity :- It is an entity that has its own existence and is independent. The entity relationship diagram represents a strong entity type with the help of a single rectangle. Below is the ERD of the strong entity type:

4. Weak Entity:- It is an entity that does not have its own existence and relies on a strong entity for its existence. The Entity Relationship Diagram represents the weak entity type using double rectangles. Below is the ERD of the weak entity type:

5. Attributes :- An attribute is a property or characteristic of an entity. An entity may contain any number of attributes. One of the attributes is considered as the primary key. In an Entity-Relation model, attributes are represented in an elliptical shape. In DBMS, there are six such types of attributes available: Simple Attributes Composite Attributes Single Valued Attributes Multi-Valued Attributes Derived Attributes Key Attributes

6. can not be subdivided into other component That contains single values It can not be subdivided into any other component Stores more than one value at a time Whose values can be derived from the other attribute Which consist of primary key (unique values) S imple Attribute Composite Attribute Single Valued Attribute Multivalued Attribute Derived Attribute Key Attribute

7. Relationship:- A Relationship represents the association between entity types. For example, ‘Enrolled in’ is a relationship type that exists between entity type Student and Course. In ER diagram, the relationship type is represented by a diamond and connecting the entities with lines.

8. Types of relationships:- 1.Unary relationship 3 . Ternary Relationship 2 . Binary relationship Ternary relationship set is a relationship set where three entity sets participate in a relationship set. 4. n- ary Relationship When there are TWO entities set participating in a relationship When there is only ONE entity set participating in a relation. When there are n entities set participating in a relation

9. Relationship examples Topics 1 3 2 4

10. Thanks!