Database Basics for Grade 13

What is a Database Model?

• A Database Model is a structure or format used to organize and define the logical design of a database.

• A Database Model is a physical implementation of a database

• A Database Model is a software used to create databases

• A Database Model is a type of computer hardware

Explain the difference between relational and non-relational database models.

• Relational databases use key-value pairs to store data.

• Non-relational databases always have a fixed schema for data storage.

• In relational databases, data is stored in tables with rows and columns based on a predefined schema, while non-relational databases store data in various formats like key-value pairs, documents, graphs, etc., without a fixed schema.

• Relational databases store data in a single table format only.

What is SQL and what is it used for in database management?

• SQL is a language used to communicate with databases, allowing users to retrieve, update, insert, and delete data.

• SQL is primarily used for creating animations in databases

• SQL is only used for data visualization in databases

• SQL is a programming language used for web development

List and explain the basic SQL commands.

• Basic SQL commands include SELECT, INSERT, UPDATE, and DELETE.

• CLEAR

• MODIFY

• ADD

What is an Entity-Relationship Diagram (ERD) and why is it important in database design?

• An Entity-Relationship Diagram (ERD) is a visual representation of the entities (objects or concepts) in a database and the relationships between them. It helps in designing a database by providing a clear overview of the structure and connections within the system.

• An ERD is a type of computer virus used to corrupt databases.

• ERDs are only used for designing websites, not databases.

• An ERD is a tool for creating animations in database systems.

Describe the components of an ERD.

• Entities, Attributes, Relationships, Primary Keys

• Tables, Columns, Indexes, Foreign Keys

• Nodes, Edges, Graphs, Paths

• Classes, Objects, Inheritance, Polymorphism

What is an entity in an ERD?

• A software program in an ERD

• A fictional character in an ERD

• A real-world object or concept represented in an ERD.

• A mathematical equation in an ERD

What is a relationship in an ERD?

• A relationship in an ERD is a type of font style for text.

• A relationship in an ERD is a mathematical formula between attributes.

• A relationship in an ERD is a color used to highlight entities.

• A relationship in an ERD represents the association between entities.

Explain the cardinality and modality in an ERD.

• Modality indicates the size of entities in an ERD.

• In an ERD, cardinality represents the number of instances of one entity that can be associated with the number of instances of another entity, while modality indicates whether the relationship is mandatory or optional.

• Cardinality represents the color of entities in an ERD.

• Cardinality is the same as modality in an ERD.

What is a primary key in a database table?

• A primary key is a unique identifier for each record in a database table.

• A primary key is a secondary identifier used for sorting data in a database table.

• A primary key is a field that can have duplicate values in a database table.

• A primary key is a random value assigned to each record in a database table.