Data analytics
Data analytics is the process of using data to answer questions about the information it represents. Databases don’t just store data; they also make that data accessible for the purposes …
Course: Introduction to Databases and SQL
Grouping data
In the previous step, you learnt about data analytics; now you are going to use SQL to perform some, specifically analysing data of computer sales. Download and open this version …
Joins
In the previous step, you used an INNER JOIN; other joins include LEFT, RIGHT, and FULL OUTER. The inner join returns only rows where there is a matching row in …
Selecting data in multiple tables
In the previous weeks of this course, you have learnt how to select and filter data from single tables using SELECT FROM WHERE statements. What if the data you needed …
Relationships
You have already explored the structure of individual tables and learnt how to retrieve data from a table. In this next activity, you will explore the relationships between tables and …
Adding a table
The database doesn’t currently hold any information about employees. A new employee table would allow you to store information about who they are, along with their contact details and contract …
Primary keys
Every table in a DBMS should have one field that uniquely identifies each record. A table containing products might use a product number to identify each record. The product number …
Welcome to week two
In week one of the course, you learnt about what a database is and explored an SQLite database of computer sales data using a DBMS (database management system). This week …
Databases and spreadsheets
Previously, you viewed and added records to your computer sales database. You may have noticed similarities between the database and a spreadsheet. You could store the data from computer sales …
The make-up of a database
It is important to understand some basic database concepts before you start exploring your computer sales database. In this step, you will be introduced to these, and also to the …
Explore a database
During this course you will be exploring and modifying an example database that tracks computer sales. Computer sales database The computer sales database you will be using is an SQLite …
Why use a database?
Databases are useful in many different scenarios for storing data. It is typical to use a database when different sets of data needs to be linked together, such as: Pupils …