S4: ERD AND SQL

What is an Entity Relationship Diagram (ERD)

• A diagram showing the layout of a database

• A drawing that shows how entities in a database are connected

• A chart showing the processing speed of a database

• A graph of user access to a database

In a database what is an entity?

• A command to retrieve data

• A specific type of attribute

• An individual item or object

• A type of database software

What are attributes in a datase?

• Rules for how data is stored

• The relationships between entities

• Properties or characteristics of an entity

• Diagrams that represent database structure

What does a one to many relationship in a database represent?

• One entity is related to many attributes

• One entity is connected to many other entities

• Each entity can have only one attribute

• Each entity can be part of only one database

What is the purpose of an SQL SELECT statement?

• To modify data in a database

• To create a new table in a database

• To retrieve data from a database

• To delete data from a database

In an ERD, what symbol typically represents a one to many relationship?

• A single line connecting two entities

• A crow's foot symbol next to one of the entities

• A circle connecting two entities

• A square symbol near one of the entities

Which of these is an example of an entity in a school database?

• A students name

• A grade in a test

• The Student table

• The relationship between students and classes

What would be an attribute for the entity Car in a database?

• The colour of the car

• The number of cars

• The price of all cars combined

• The database containing car information

Which SQL statement is written correctly to retrieve all data from a table named Students?

• SELECT all FROM Students;

• RETRIEVE * FROM Students;

• SELECT * FROM Students;

• GET * Students;

In a one to many relationship, what is true about the 'one' side?

• It can only have one record

• It refers to the primary key in an entity

• It must have many attributes

• It cannot connect to other entities