Database Software

Lesson 4 of 8 · Software for Data Work 101 · Beginner

When your data outgrows a spreadsheet — or when you need multiple people to access the same data reliably — a database is the right tool. Databases are designed specifically for storing, organizing, and retrieving structured data at scale.

What Is a Database?

A database is an organized collection of structured data, managed by software called a database management system (DBMS). Unlike a spreadsheet, a database enforces rules about data types, relationships between tables, and who can access or modify data.

Relational Databases

The most common type of database for data work is the relational database. In a relational database, data is stored in tables — similar to spreadsheet sheets — but with important differences:

• Each table has a defined structure: specific columns with specific data types
• Tables can be linked to each other through shared keys
• The database enforces rules to prevent invalid data from being entered
• Multiple users can read and write data simultaneously without conflicts

For example, a database for a small organization might have a table for clients, a table for projects, and a table for invoices — all linked together so you can query across them.

Querying with SQL

SQL (Structured Query Language) is the standard language for interacting with relational databases. A query is a request for data — you write instructions that tell the database what to retrieve, filter, sort, or calculate.

A simple SQL query looks like this:

SELECT name, city
FROM clients
WHERE province = 'ON'
ORDER BY name;

This retrieves the name and city of all clients in Ontario, sorted alphabetically. SQL is a foundational skill for anyone working with databases regularly.

When Do You Need a Database?

Consider moving from a spreadsheet to a database when:

• Your dataset has more than a few thousand rows and is growing
• Multiple people need to read and write data at the same time
• You need to enforce data quality rules automatically
• You need to link data across multiple tables
• You need to automate data processing or reporting

Related learning: Metadata 101 covers how to document your data structures — essential when working with databases.