532 Database management

Databases store, retrieve, and manage the data that powers dynamic web applications, enabling content to change based on user input or system logic.

Outline

This section introduces how web applications use databases to store and access structured data. Students explore relational databases using SQL, learn how to write queries to filter and join data, and compare the SQL approach to Object-Relational Mapping (ORM). They also examine how back-end systems use queries and data models to generate dynamic content and respond to user requests.

This section builds on students’ understanding of back-end programming and prepares them to integrate database access into full-stack applications.

Targets

In this topic, students learn to:

• Write SQL queries to retrieve and manipulate data from a database

• Apply filtering, sorting, and joining techniques using SQL syntax

• Construct scripts that execute SQL from a web application

• Compare ORM with traditional SQL-based queries

• Connect web applications to relational or NoSQL databases

Glossary

Term	Definition
Database	A structured collection of data that can be queried and modified
SQL	Structured Query Language used to manage and query relational databases
Query	A command used to retrieve, insert, update, or delete data in a database
Join	A SQL operation that combines data from multiple tables based on related keys
WHERE clause	A condition in a query that filters results based on specified criteria
Group by	A SQL clause that aggregates data into categories for summary results
ORM	Object-Relational Mapping; a programming method that interacts with databases using objects instead of SQL commands
NoSQL	A flexible, non-relational approach to storing data (e.g. document-based, key-value, graph)

Overview

Databases are essential for web applications that require persistent storage of user data, content, or system records. Whether logging in, placing an order, or browsing dynamic content, users rely on databases behind the scenes.

This section focuses on teaching students how to write SQL queries that support the back-end of a web application. Students learn to connect databases to a web framework, execute queries through code, and display results dynamically. They also explore the trade-offs between writing raw SQL and using an ORM, helping them choose the right tool for their application.