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keshav Sandhu
keshav Sandhu

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Prisma Recap: Everything You Need in 5 Minutes (cheat sheet) 🐳

Here's a complete cheat sheet for Prisma, covering essential concepts, commands, and operations that you’ll often use when working with Prisma in full-stack applications.


Prisma Cheat Sheet

1. Installation and Setup

Install Prisma CLI

npm install prisma --save-dev
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Initialize Prisma

Sets up prisma directory and a .env file.

npx prisma init
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2. Prisma Schema

The Prisma schema is where you define your data models, database connection, and Prisma Client generation.

Basic Structure

datasource db {
  provider = "postgresql"  // Database provider (e.g., postgresql, mysql, sqlite)
  url      = env("DATABASE_URL")  // Connection URL from .env file
}

generator client {
  provider = "prisma-client-js"  // Client generator
}

model User {
  id    Int    @id @default(autoincrement())  // Auto-increment primary key
  name  String
  email String @unique  // Unique email field
}
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Data Types

  • Int, String, Boolean, Float, DateTime
  • @id: Primary Key
  • @unique: Unique field constraint
  • @default: Default values (e.g., autoincrement(), now())

3. Migrations

Prisma migrations help in managing schema changes in your database.

Create Migration

Generates a migration based on changes in the Prisma schema.

npx prisma migrate dev --name <migration_name>
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Apply Pending Migrations

Apply migrations to the database.

npx prisma migrate deploy
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Reset the Database

Reset the database by applying migrations from scratch.

npx prisma migrate reset
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4. Prisma Client

Prisma Client is an auto-generated and type-safe query builder.

Generate Prisma Client

After modifying the schema, generate Prisma Client.

npx prisma generate
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Import and Initialize Prisma Client

import { PrismaClient } from '@prisma/client';
const prisma = new PrismaClient();
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5. CRUD Operations

Create

const newUser = await prisma.user.create({
  data: {
    name: "Alice",
    email: "alice@example.com",
  },
});
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Read

const users = await prisma.user.findMany();
const user = await prisma.user.findUnique({
  where: { email: "alice@example.com" },
});
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Update

const updatedUser = await prisma.user.update({
  where: { id: 1 },
  data: { name: "Alice Updated" },
});
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Delete

const deletedUser = await prisma.user.delete({
  where: { id: 1 },
});
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Upsert (Create or Update)

const user = await prisma.user.upsert({
  where: { email: "alice@example.com" },
  update: { name: "Updated Alice" },
  create: { name: "Alice", email: "alice@example.com" },
});
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6. Query Filters

Basic Filtering

const users = await prisma.user.findMany({
  where: {
    name: "Alice",  // Exact match
  },
});
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Advanced Filtering

  • contains: Check if a string contains a value.
  • startsWith: Check if a string starts with a value.
  • endsWith: Check if a string ends with a value.
const users = await prisma.user.findMany({
  where: {
    email: { contains: "@example.com" },
  },
});
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Filtering with Conditions (AND, OR, NOT)

const users = await prisma.user.findMany({
  where: {
    AND: [
      { name: "Alice" },
      { email: { contains: "@example.com" } },
    ],
  },
});
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7. Relations

One-to-Many

Define a Post model related to User.

model User {
  id    Int     @id @default(autoincrement())
  name  String
  posts Post[]  // A user has many posts
}

model Post {
  id     Int    @id @default(autoincrement())
  title  String
  userId Int
  user   User   @relation(fields: [userId], references: [id])  // Post belongs to a user
}
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Querying Relations

  • Include Related Data: include
  • Filter by Related Data: where

Fetch a user and their posts:

const userWithPosts = await prisma.user.findUnique({
  where: { id: 1 },
  include: { posts: true },  // Include posts in the result
});
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8. Transactions

Atomic Transactions

Execute multiple queries in a single transaction.

const [user, post] = await prisma.$transaction([
  prisma.user.create({ data: { name: "Alice" } }),
  prisma.post.create({ data: { title: "Hello World", userId: 1 } }),
]);
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9. Pagination

Skip and Take

const users = await prisma.user.findMany({
  skip: 10,   // Skip the first 10 users
  take: 5,    // Fetch the next 5 users
});
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10. Aggregations

Prisma allows you to perform aggregations such as counting, averaging, summing, etc.

Count

const userCount = await prisma.user.count();
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Average

const avgAge = await prisma.user.aggregate({
  _avg: {
    age: true,
  },
});
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Group By

const postsByUser = await prisma.post.groupBy({
  by: ['userId'],
  _count: {
    _all: true,  // Count all posts per user
  },
});
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11. Soft Deletes (Optional)

You can implement soft deletes by adding a deletedAt field and filtering records accordingly.

model User {
  id        Int      @id @default(autoincrement())
  name      String
  deletedAt DateTime?  // Optional timestamp for soft deletes
}
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Querying Non-Deleted Records

const activeUsers = await prisma.user.findMany({
  where: {
    deletedAt: null,  // Only fetch users that are not soft-deleted
  },
});
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12. Environment Variables (.env)

Prisma uses a .env file to manage environment variables, such as your database connection URL.

Example .env:

DATABASE_URL="postgresql://user:password@localhost:5432/mydb"
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13. Seeding the Database

Seeding is helpful for adding initial or sample data to the database.

Seed Script

  1. Define the seed script in package.json:
   "prisma": {
     "seed": "node prisma/seed.js"
   }
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  1. Implement the seed file:
   const { PrismaClient } = require('@prisma/client');
   const prisma = new PrismaClient();

   async function main() {
     await prisma.user.create({
       data: {
         name: "Alice",
         email: "alice@example.com"
       },
     });
   }

   main();
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  1. Run the seed:
   npx prisma db seed
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Key Commands Recap

Command Description
npx prisma init Initialize Prisma
npx prisma migrate dev Create and apply a migration
npx prisma migrate reset Reset the database
npx prisma generate Generate Prisma Client
npx prisma db seed Run the seed script
npx prisma studio Launch Prisma Studio (GUI for database)

This cheat sheet covers the essential Prisma features you’ll need for most projects. Keep in mind that Prisma is highly versatile and works with relational databases, making it an excellent ORM for modern web development.

Top comments (2)

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onesamket_dev profile image
Tewodros Birhanu

Wow! This is the most amazing article I've ever read about Prisma. It's clean, clear, and concise.

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keshav___dev profile image
keshav Sandhu

thanks