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Module 10 — PostgreSQL & SQL

Why You Need to Know SQL​

Even if you use an ORM like Prisma for day-to-day work, understanding SQL makes you far more effective:

  • Debug ORM-generated queries
  • Write efficient complex queries an ORM can't express cleanly
  • Understand indexes and performance
  • Migrate data safely
  • Pass technical interviews

Learning Objectives​

  • Create databases and tables with correct data types
  • Write SELECT, INSERT, UPDATE, DELETE queries
  • Use WHERE, ORDER BY, GROUP BY, LIMIT
  • Join tables with INNER JOIN, LEFT JOIN
  • Use aggregate functions: COUNT, SUM, AVG, MAX, MIN
  • Create indexes and understand when to use them
  • Understand ACID guarantees

Module Lessons​

  1. Databases Intro
  2. SQL Fundamentals
  3. Joins & Relations
  4. Indexes & Performance

Tools​

# Install PostgreSQL (Mac)
brew install postgresql@16
brew services start postgresql@16

# Or use Docker (recommended)
docker run --name postgres -e POSTGRES_PASSWORD=password -p 5432:5432 -d postgres:16

# Connect with psql
psql -U postgres

# GUI: TablePlus (free tier) or pgAdmin

Challenge​

Build an Employee Tracker CMS — a CLI app that manages a company's employees, roles, and departments using a real PostgreSQL database.

View Challenge →