Master SQL for Data Analysis - Relational Model, ER Diagram

The video tutorial explains the structure of relational databases, focusing on columns, rows, primary and foreign keys. It introduces the relational model's building blocks: entities, attributes, and relationships, and discusses entity relationship diagrams (ERDs) as tools for illustrating database structures. The tutorial emphasizes using ERDs to optimize queries by understanding entity connections and available attributes.

What is the primary purpose of a primary key in a relational database?

• To define relationships between tables

• To uniquely identify each row

• To store data types

• To link tables together

Which of the following is NOT an example of an entity in a relational model?

• A student

• A city

• A data type

• A meeting

In a relational model, what is an attribute?

• A type of relationship

• A diagram illustrating data flow

• A characteristic of an entity

• A unique identifier for a table

Which type of relationship describes a scenario where one entity is associated with many others?

• None of the above

• One-to-many

• One-to-one

• Many-to-many

What is the main purpose of an Entity Relationship Diagram (ERD)?

• To store data in tables

• To illustrate how entities relate to each other

• To define data types

• To optimize database queries