1.3 Exchanging data [1.3.2]

What is a database?

An organized collection of data that is stored electronically

What is a relational database?

A database that has a relationship

What are the types of relationships?

One to one, one to many, many to many

What is a primary key?

A key that can identify each attribute separately

What is a secondary key?

A key that can be used to quickly search for an item in a table

What is a foreign key?

A key that allows you to establish a relationship with another table

What is normalisation?

The process coming up with the best possible design for a relational database

What is the First Normal Form (1NF)?

This is where the relational database contains no repeating attributes

What is the Second Normal Form (2NF)?

This is where the relational database is in 1NF and contains no partial dependencies

What is the Third Normal Form (3NF)?

This is where the relational database is in 2NF and has no non key dependencies

What is SQL used for?

Structured Query Language allows for fast and efficient retrieval, deletion and manipulation of data

How do you select data?

SELECT population
FROM world
WHERE name = "Albania"

What is a wildcard?

A single character can be used to represent all fields of a table

How do you insert data?

INSERT INTO world (name, capital, population)
VALUES ("Oz", "Emerald City", 1000000)

How do you delete data?

DELETE FROM world
WHERE name LIKE = "Al%"

How do you join tables?

JOIN Tutor_Group
ON Student.Tutorgroup = Tutor_Group.Tutorgroup

How do you delete a table

DROP TABLE <table name>