Prisma ORM - Schema, Client & Migrations

Prisma is a type-safe ORM for Node.js. Its schema.prisma file is the single source of truth for your data model - the Prisma Client is auto-generated from it, giving you full TypeScript type safety on every query. Prisma Migrate keeps your database schema in sync with your code.

30 min•By Priygop Team•Updated 2026

Installation & Setup

npm install prisma @prisma/client
npx prisma init --datasource-provider postgresql

# This creates:
# prisma/schema.prisma  ← your database schema
# .env                  ← DATABASE_URL

# schema.prisma
# generator client {
#   provider = "prisma-client-js"
# }
# datasource db {
#   provider = "postgresql"
#   url      = env("DATABASE_URL")
# }

Schema Definition

// prisma/schema.prisma

model User {
  id        String   @id @default(uuid())
  email     String   @unique
  name      String
  role      Role     @default(USER)
  password  String   // hashed - never store plaintext
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  posts     Post[]           // one-to-many
  profile   UserProfile?     // one-to-one (optional)

  @@index([email])           // index for fast lookups
  @@map("users")             // actual table name
}

enum Role { USER ADMIN MODERATOR }

model Post {
  id          String   @id @default(uuid())
  title       String
  content     String   @db.Text   // TEXT column (unlimited length)
  published   Boolean  @default(false)
  authorId    String
  categoryId  String?
  
  author      User       @relation(fields: [authorId], references: [id], onDelete: Cascade)
  category    Category?  @relation(fields: [categoryId], references: [id])
  tags        Tag[]      // many-to-many via implicit join table

  createdAt   DateTime   @default(now())
  updatedAt   DateTime   @updatedAt

  @@index([authorId])
  @@index([published, createdAt(sort: Desc)])  // compound index
  @@map("posts")
}

model Category {
  id    String  @id @default(uuid())
  name  String  @unique
  slug  String  @unique
  posts Post[]
  @@map("categories")
}

model Tag {
  id    String @id @default(uuid())
  name  String @unique
  posts Post[]
  @@map("tags")
}

model UserProfile {
  id     String  @id @default(uuid())
  bio    String?
  avatar String?
  userId String  @unique
  user   User    @relation(fields: [userId], references: [id], onDelete: Cascade)
  @@map("user_profiles")
}

# Commands:
# npx prisma migrate dev --name init    ← create migration, apply, regenerate client
# npx prisma migrate deploy              ← apply in production (no dev tooling)
# npx prisma db push                     ← sync schema without migration (prototyping)
# npx prisma studio                     ← browser-based DB GUI

Tip

Practice Prisma ORM Schema Client Migrations in small, isolated examples before integrating into larger projects. Breaking concepts into small experiments builds genuine understanding faster than reading alone.

Diagram

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Technical diagram.

Practice Task

Note

Practice Task - (1) Write a working example of Prisma ORM Schema Client Migrations from scratch without looking at notes. (2) Modify it to handle an edge case (empty input, null value, or error state). (3) Share your solution in the Priygop community for feedback.

Quick Quiz

Common Mistake

Warning

A common mistake with Prisma ORM Schema Client Migrations is skipping edge case testing - empty inputs, null values, and unexpected data types. Always validate boundary conditions to write robust, production-ready node code.

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