Logical Design Flashcards
Key fields (Primary)
Definition, Purpose & Example of?
Primary Key:
Definition: A primary key is a field or combination of fields that uniquely identifies each record in an entity.
Purpose: Ensures data integrity and uniqueness within the entity.
Example: In a “Customer” entity, the primary key could be “CustomerID” to uniquely identify each customer.
Key fields (Foreign)
Definition, Purpose & Example of?
Foreign Key:
Definition: A foreign key is a field in one entity that establishes a relationship with the primary key of another entity.
Purpose: Enables the establishment of relationships and maintains data integrity across entities.
Example: In an “Order” entity, a foreign key “CustomerID” can link to the primary key of the “Customer” entity.
Entities
Definition, purpose and example
Entities:
Definition: An entity represents a distinct object or concept within a system.
Purpose: Organizes and categorizes data within the system.
Example: Entities in an e-commerce system could include “Product,” “Customer,” and “Order.”
Attributes
Definition, purpose and example
Attributes:
Definition: Attributes are properties or characteristics of an entity.
Purpose: Describes the specific details or data associated with an entity.
Example: Attributes for the “Product” entity could include “ProductID,” “ProductName,” “Price,” and “Description.”
Functional Requirements:
Definition, purpose and example
Functional Requirements:
Definition: Functional requirements specify the desired system functionality and behavior.
Purpose: Guides the development process to meet user needs and system objectives.
Example: A functional requirement for a banking system could be “Allow customers to transfer funds between accounts.”
Non Functional Requirements:
Definition, purpose and example
Non-functional Requirements:
Definition: Non-functional requirements define the system characteristics and constraints.
Purpose: Specifies quality attributes such as performance, security, and usability.
Example: A non-functional requirement could be “Ensure the system response time is less than two seconds for a search operation.”
Storyboarding:
Definition
Purpose
Example
Storyboarding:
Definition: Storyboarding is a visual representation or flowchart of the system’s user interface and interactions.
Purpose: Illustrates the intended user experience and navigation through the system.
Example: A storyboard for a mobile banking app may depict screens for login, account balance, transaction history, and funds transfer.
Data Dictionaries:
Definition, Purpose, Example
Data Dictionaries:
Definition: A data dictionary provides detailed information about each data element in the system.
Purpose: Offers a comprehensive reference for data elements, their attributes, and constraints.
Example: A data dictionary entry for a “Customer” entity could include attributes like “CustomerID” (integer), “Name” (string), “Email” (string), and their respective descriptions, lengths, and validation rules.
