A Practical Guide to Modeling, Normalizing, and Building Relational Databases

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Design databases that stay correct, fast, and easy to change — even if you have never written SQL.

Almost every app and business system keeps its information in a database. When the design is good, nobody notices. When it is poor, everyone feels it: duplicate customers, totals that disagree, impossible records, and changes that take weeks. Database design is a learnable skill, and this book teaches it from the very beginning, one clear step at a time.

What's inside

• What a relational database is, and how tables, rows, columns, and data types work
• Setting up PostgreSQL and a free database client, plus just enough SQL to build and query your design
• Primary keys, natural vs surrogate keys, and uniqueness
• Turning real requirements into entities and relationships, and drawing ER diagrams
• One-to-many, many-to-many, one-to-one, and self-referencing relationships with foreign keys
• Normalization explained simply: anomalies, 1NF, 2NF, 3NF, BCNF, and when to denormalize on purpose
• Constraints, ON DELETE rules, NULL handling, and everyday patterns for status, money, dates, addresses, and history
• Joins, reporting queries, indexes, views, transactions, and reading query plans
• Changing a live schema safely, roles and permissions, SQL injection, and protecting personal data
• Common anti-patterns and a design review checklist

One running example, start to finish. You design the database for Ovenly, a fictional three-shop bakery with online pre-orders, a loyalty program, suppliers, recipes, and staff shifts, replacing a messy spreadsheet with a clean relational design.

Written for beginners. No prior database or SQL knowledge needed. Every term is explained when it first appears, with sample-data tables, Tips, Notes, Warnings, practice exercises, and Key Takeaways in every chapter. Differences between PostgreSQL, MySQL, SQLite, and SQL Server are pointed out where they matter.

Format: PDF, 404 pages (A4), linked table of contents and bookmarks. English. First Edition, 2026. Published by thenexbooks.

Table of Contents

Part I — Database Foundations

• Ch 1 · What Is a Database? Data, Tables, and Why Design Matters
• Ch 2 · Setting Up: PostgreSQL, a Database Client, and Your First Database
• Ch 3 · Tables, Rows, Columns, and Choosing Data Types
• Ch 4 · SQL Basics for Designers: CREATE, INSERT, SELECT, UPDATE, and DELETE
• Ch 5 · Keys: Primary Keys, Natural and Surrogate Keys, and Uniqueness

Part II — Modeling Data

• Ch 6 · From Requirements to Data: Stories, Nouns, and Business Rules
• Ch 7 · Entity-Relationship Modeling: Entities, Attributes, and Relationships
• Ch 8 · One-to-Many Relationships and Foreign Keys
• Ch 9 · Many-to-Many Relationships and Junction Tables
• Ch 10 · One-to-One, Optional Relationships, and Self-References

Part III — Normalization

• Ch 11 · Why Normalize? Redundancy and Update Anomalies
• Ch 12 · First Normal Form: Atomic Values and No Repeating Groups
• Ch 13 · Second and Third Normal Form
• Ch 14 · Beyond Third Normal Form: BCNF and Knowing When to Stop
• Ch 15 · Denormalization: Deliberate Trade-offs

Part IV — Integrity and Patterns

• Ch 16 · Constraints: NOT NULL, UNIQUE, CHECK, and DEFAULT
• Ch 17 · Referential Integrity: ON DELETE, ON UPDATE, and Cascades
• Ch 18 · NULL, Missing Data, and Optional Values
• Ch 19 · Everyday Modeling Patterns: Lookup Tables, Status, Money, Dates, Addresses, and History

Part V — Querying and Performance

• Ch 20 · Joins: Reading Your Design Back
• Ch 21 · Aggregation and Reporting Queries
• Ch 22 · Indexes Explained
• Ch 23 · Views, Transactions, and Keeping Data Consistent
• Ch 24 · Designing for Performance: Query Plans and Common Mistakes

Part VI — Real-World Design

• Ch 25 · Changing a Schema Safely: Migrations and Versioning
• Ch 26 · Security Basics: Users, Roles, Permissions, and Sensitive Data
• Ch 27 · Design Review: Anti-Patterns and a Checklist
• Ch 28 · Case Study: Designing the Ovenly Database from Scratch

Appendices
A · SQL and Design Cheat Sheet
B · Templates and Data Type Reference
C · Design Review Checklist
D · Glossary

Book details