Topic 5 - Databases

What is a relational database?

• A database that is built from a set of unique tables containing data about one entity
•  A database with one single large table
•  A set of many databases about numerous, related topics

What is normalisation?

•  Making databases larger so that they are easier to use
•  Analysing how to make databases more efficient by using separate tables to reduce redundant data
•  Setting the correct data types to all of the data in a database

 Setting the correct data types to all of the data in a database

• Built from a set of unique tables, each with a primary key, linked together with relationships
•  Built upon one large table containing all the attributes, used to record a limited amount of data
• A collection of separate tables in which all the data for the system is stored

What is a foreign key?

•  A foreign key is a primary key that appears in another table to create a relationship between the two tables
•  A foreign key is a field that does not belong in that table
•  A foreign key is a field that is a unique identifier in that entity

What would you use a query for?

• To export and present information from a database
•  To enter data into a database
•  To search and filter a database

What is an entity?

• A table in a database
•  A field in a database
•  A record in a database

Why would you create a report?

•  To store data in the database
•  To present data in a user-friendly way
•  To search the database

What type of relationship exists between a person and national insurance number?

• One to One
• One to Many
• Many to Many

What type of relationship exists between courses and students?

• What type of relationship exists between courses and students?
• One to Many
• Many to Many

What type of relationship exists between a company and employees?

• What type of relationship exists between a company and employees?
• One to Many
•  Many to Many