Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Introduction to Database > Unit 3 : Data Model > Flashcards

Unit 3 : Data Model Flashcards

1
Q

What is entity?

A
  1. Anything about which data are collected and stored
  • Example : In a school database, students, teachers, and courses could all be considered entities.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is attribute?

A
  1. A characteristic of an entity
    ( Column inside like Student table - name, studentID , address )
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is relationship?

A
  1. Association among entities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

List out the relationship types ( 3 )

A
  1. One-to-many ( 1 : M ) relationship
  2. Many-to-many ( M : N or M : M ) relationship
  3. One-to-one ( 1: 1 ) relationship
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is constraint?

A
  1. A restriction placed on the data
  • IS NULL, NOT NULL, UNIQUE, CHECK
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

List out examples for one-to-many relationship

A
  1. One student can enroll in many courses, but each course is taught by only one instructor
  • Where one entity can be associated with many instances of another entity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

List out the example for many-to-many relationship

A
  1. Students can enroll in many courses, and courses can have many students
  • Where many instances of one entity can be associated with many instances of another entity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

List out the examples for one-to-one relationship

A
  1. A department head leads one department and that department is led by only one department head
  • Where one instance of an entity is associated with exactly one instance of another entity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the sources of business rules? ( 5 )

A
  1. Company managers
  2. Policy makers
  3. Department managers
  4. Written documentation
    • Procedures
    • Standards
    • Operations Manuals
  5. Direct interviews with end users
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Who invented the relational model?

A
  1. Codd ( IBM ) in 1970
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

List out 4 of the evolution of data models

A
  1. Hierarchical
  2. Network
  3. Relational
  4. Entity Relationship
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does relational model consists? ( 12 ）

A
  1. Table
  2. Relational Diagram
  3. Keys ( Primary Key )
  4. Relationship ( one-to-many )
  5. Normalization ( Process of organizing data in a database to reduce redundancy and improve data integrity )
  6. Contraints ( NOT NULL , UNIQUE , CHECK )
  7. Indexes
  8. SQL ( Strutured Query Language)
  9. Data Integrity
  10. Views
  11. Stored Procedures and Triggers
  12. Transactions
    * Use in MySQL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does table consists?

A
  1. Consist a series of row and column intersections
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is data model?

A
  1. It is a relatively simple representations, usually graphical, of complex real-world data structures
  • ERD is one of the data model
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why are data models important in database design ?

A
  1. It facilitate interaction among the designer, the applications programmer, and the end user
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How data models help end users?

A
  1. It provides differents views and needs for data for end-users
17
Q

How entities are used in database? ( 2 )

A
  1. Tables
  2. Relationship ( Customer table have a relationship between Order table )
18
Q

What is instances?

A
  1. Refers to a specific, individual example or occurrence of an entity in a database
  • Example : Customer consists Name, Email, ID, which instances is the value ( row ) inside the table, which means John Smith, john@gmail.com, 13
19
Q

Why should we learn business rules in database?

A
  1. To know the design and operation of databases within an organization
20
Q

What are business rules ? ( Characteristics )

A
  1. It was a brief, precise, and unambiguous descriptions of policies, procedures, or principles within a specific organization
21
Q

What types of organizations do business rules apply? ( Characteristics )

A
  1. Apply to any organization that stores and uses data to generate information ( Characteristics )
22
Q

What do business rules describe within an organization? ( Characteristics )

A

1.Describe the operations that help to create and enforce actions within the organization’’s environment

23
Q

Is what form must business rules be rendered ? ( Characteristics )

A
  1. Must be rendered in writing
24
Q

How often should business rules be updated? ( Characteristics )

A
  1. Must be kept up to date
25
Q

Can business rules originate outside of the organization? ( Characteristics )

A
  1. Yes
26
Q

What are the 2 key characteristics of business rules in terms of undertanding and dissemination?

A
  1. Must be easy to understand and widely disseminated
27
Q

What aspect of data do business rules describe as viewed by the company? ( Characteristics )

A
  1. Business rules describe the characteristics of the data as viewed by the company.
28
Q

How to translate Business Rules into Database Concepts? ( 3 )

A
  1. Nouns translate into entities
    • Customer , Order table
  2. Verbs translate into relationships among entities
    • Relationship between Customer and Order table
  3. Relationships are bi-directional
    • We can find all orders for a customer and find the customer for a given order )
29
Q

What concepts that database system integrates? ( 2 )

A
  1. The Relational Models
  2. The Entity Relationship Model
30
Q

What is the key concepts in the relational models ( 5 )

A
  1. Tables : Represent entities.
  2. Columns : Represent attributes of entities.
  3. Primary Keys : Uniquely identify each row in a table.
  4. Foreign Keys: Establish relationships between tables.
  5. Normalization: Ensures data integrity and reduces redundancy.
31
Q

What is the key concepts in the entity relationship models ( 4 )

A
  1. Entities : Objects or things about which data is collected (e.g., Customer, Order).
  2. Attributes : Characteristics of entities (e.g., CustomerName, OrderDate).
  3. Relationships : Associations between entities (e.g., “Customer places Order”).
  4. ER Diagrams : Graphical representations of entities, attributes, and relationships, used for designing the database schema.
32
Q

List out the symbols used to represent one and many in the entity relationship model ( 2 )

A
    • ||
  2. ||< ( Have a - inside < )
33
Q

Which model is widely accepted and adapted graphical tool for data modeling?

A
  1. The entity relationship model
34
Q

Who introduced the entity relationship model

A
  1. Chen
35
Q

What is diamond shape in the entity relationship model?

A
  1. To connect related entities through a relationship line
36
Q

What does relational table resembles?

A
  1. A file
37
Q

Which model is purely logical structure? And why

A
  1. Relational Table
  2. How data are physically stored in the database is of no concern to the user or the designer
  3. This property became the source of a real database revolution

Introduction to Database (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions