Free online courseDatabase

Course Description

Build practical database skills you can use in real projects, from the first idea of how to structure data to the moment your system must run reliably at scale. This free online course guides you through the foundations behind modern data applications, helping you reason about what a database management system offers, why data models matter, and how good design choices prevent painful rework later. You will gain a clear, structured understanding of how data is represented, validated, queried, secured, and kept consistent over time.

You will start by developing an intuition for the relational model, including keys and the way relationships shape integrity and query power. From there, you will move into the mindset of querying: thinking in operations, composing results, and expressing questions precisely. Along the way, you will also explore how semi-structured data fits into the ecosystem, with a solid introduction to XML and JSON, why they are used, and what makes them different from relational data. You will learn how schemas and validation approaches influence data quality, interoperability, and long-term maintainability.

SQL becomes a hands-on tool rather than a mystery. You will learn to write queries that stay readable as complexity grows, use joins and subqueries thoughtfully, apply aggregation correctly, and understand how null values affect logic. You will also work with the statements that change data, so you can move from simply reading tables to building systems that evolve. Behind the scenes, the course connects query behavior to core ideas such as relational algebra, strengthening your ability to debug results and reason about performance.

As your understanding deepens, you will tackle design quality through functional dependencies and normalization, learning how to avoid anomalies and store data in ways that scale. You will also see how database features support reliability and governance: indexes for speed, constraints and referential integrity for correctness, triggers for controlled automation, transactions with ACID guarantees, and isolation levels that explain real-world concurrency. You will explore views, including materialized options, and touch on authorization and analytical workloads, finishing with perspective on NoSQL motivations and where alternative systems fit best. By the end, you will be able to design stronger schemas, write confident SQL, and make informed trade-offs when building data-driven applications.