Prisma

Prisma is a modern database toolkit that makes database access easy with auto-generated type-safe queries and a visual database browser.

Why use Prisma?

• Auto-Generated Types: Fully typed client generated from your schema
• Prisma Studio: Visual database browser for exploring and editing data
• Migration System: Declarative migrations with automatic SQL generation
• Introspection: Generate Prisma schema from existing database
• Developer Experience: Excellent IntelliSense and error messages
• Active Development: Large community and frequent updates

Requirements: Database (PostgreSQL or MySQL)

Technical Changes

Package Structure

• Turborepo mode: Creates packages/db/ with @repo/db package
• Single repo mode: Database logic in app's src/lib/db/ directory

Dependencies

• package.json includes:
  • @prisma/client: Auto-generated database client
  • prisma (dev): CLI for migrations and introspection

Scripts

• build: Compile package to dist/index.js (turborepo only)
• db:generate: Generate Prisma Client from schema
• db:pull: Introspect database and update schema
• db:push: Push schema to database without migrations (dev)
• db:studio: Launch Prisma Studio visual editor
• db:seed: Run seed script to populate database

Prisma Schema

• Creates prisma/schema.prisma with:
  • Generator: prisma-client-js with custom output path (turborepo: ../generated/prisma)
  • Datasource: Provider postgresql or mysql, URL from env
  • User Model: id (uuid), username (unique), email (unique), emailVerified, avatarUrl, phone, firstName, lastName, timestamps
  • Post Model: id (uuid), title, content, published, authorId (FK), timestamps, author relation
  • Relations: User hasMany Posts, Post belongsTo User with onDelete: Cascade
  • Better Auth Models (conditional if better-auth module selected):
    • Session Model: id, userId (FK), token (unique), expiresAt, ipAddress, userAgent, timestamps
    • Account Model: id, userId (FK), accountId, providerId, tokens, scope, idToken, password, timestamps
    • Verification Model: id, identifier, value, expiresAt, timestamps

Database Client

• Creates src/index.ts:
  • PrismaClient singleton pattern with global caching (prevents hot-reload connection issues)
  • Logging: query, error, warn in development; error only in production
  • Re-exports all Prisma Client types
  • Type Helpers:
    • User, Post: Basic model types
    • UserWithPosts: User with posts included
    • PostWithAuthor: Post with author included
    • Session, Account, Verification (conditional): Better Auth types

Environment

• Creates .env.example:
  • DATABASE_URL template with connection string format

Seed Script

• Creates scripts/seed.ts:
  • Clears existing data with .deleteMany() (posts, users)
  • Creates 2 sample users (Alice, Bob) with .create()
  • Creates 3 sample posts with .createMany() (2 published, 1 draft)
  • Demonstrates Prisma Client API and relations
  • Properly disconnects with $disconnect() in finally block