Prisma

This is a cheat sheet repo for the Prisma database ORM. Prisma is a database toolkit that makes it easy to query, migrate and model your database

Prisma can use any database, but this cheat sheet is focused on PostgreSQL (Note: Very little would change with a different database, that's the magic of Prisma)

Table of Contents

• Prisma
  • Table of Contents
  • Installation
    • Initialize Prisma
  • Setup a Database
    • IF you already have data in your database
    • *Prisma VS Code Extension
  • Define your Database Schema
  • Initialize your database
  • Install Prisma Client
  • Use Prisma Client
  • Schema Models
    • Enums
  • CRUD Operations
    • CREATE
    • UPDATE
    • CONNECT, DISCONNECT, SET
    • DELETE
    • READ
  • FILTERS
  • Resources
  • License

Installation

• setup a new project with npm init -y
• install Prisma and needed dev dependencies with npm i -D prisma @prisma/client

Note: For a Typescript project, you'll need to install typescript and ts-node as well as well as any other dev dependencies you need for your project (such as @types/node for a Node project)

It is also recommended to install nodemon for development

• Full Command for a Node Typescript Project

npm i -D prisma typescript ts-node @types/node nodemon

• create a tsconfig.json file:

{
  "compilerOptions": {
    "sourceMap": true,
    "outDir": "dist",
    "strict": true,
    "lib": ["esnext"],
    "esModuleInterop": true
  }
}

Initialize Prisma

• this will create a prisma folder with a schema.prisma file

npx prisma init --datasource-provider postgresql

--datasource-provider is optional and will default to postgresql

Setup a Database

• Setup any database you want to use with Prisma and get the connection string

Note: I've created a new database with Supabase which is a firebase-like database service that uses PostgreSQL

• Create a new database with Supabase

• Go to Project Settings / Database / Connection string / URI and copy the URI string

• Add your database connection URI string to .env

DATABASE_URL="postgresql://USER:PASSWORD@HOST:PORT/DATABASE?schema=SCHEMA"

Note: After 2023, you probably need to copy/paste another DATABASE_URL from supabase

IF you already have data in your database

• run npx db pull if you already have data in your database and you want to generate the Prisma schema

• add your schema in schema.prisma

*Prisma VS Code Extension

Install the prisma vs-code extension for syntax highlighting and more

Add the following to your settings.json file to enable this extension for .prisma files:

"[prisma]": {
  "editor.defaultFormatter": "Prisma.prisma"
}

Define your Database Schema

• Define your database models

model User {
id String @id @default(uuid())
name String
}

Note: uuid is of type String, autoincrement is of type Int

Initialize your database

Remember to run this command after any changes to your schema

npx prisma migrate dev

if prisma complains, run this command: npx prisma migrate dev --name init

Install Prisma Client

npm i @prisma/client

When you install Prisma Client, it automatically generates a client for your defined models, if you need to regenerate the client, run npx prisma generate

Use Prisma Client

• create a prisma.ts or any file you want to use Prisma in

• import the client

import { PrismaClient } from '@prisma/client'

• create a new instance of the client

const prisma = new PrismaClient()

Note: Tell prisma to log all database queries Useful WHEN debugging

const prisma = new PrismaClient({
  log: ['query', 'info', 'warn'],
})

• use the client to query your database

async function main() {
  const allUsers = await prisma.user.findMany()
  console.log(allUsers)
  // ... WRITE HERE ALL YOUR QUERIES
}
main()
  .catch((e) => {
    throw e
  })
  .finally(async () => {
    await prisma.$disconnect()
  })

Note: Check the example project in this repo for prisma client and schema models examples

Schema Models

• schema.prisma file

model User {
id String @id @default(uuid()) // @id sets the primary key
// id Int @id @default(autoincrement())
email String @unique // @unique sets the field as unique
name String? // ? optional
createdAt DateTime @default(now()) // * default value (now)
updatedAt DateTime @updatedAt // * auto update this field on update

posts Post[] // * one user to many posts relation

// ? BLOCK LEVEL ATTRIBUTE
@@unique([age, name]) // now we cannot have two users with the same age and name
@@index([email]) // index this field for faster queries when filtering and sorting
}

model Post {
id String @id @default(uuid())
title String
content String?
published Boolean @default(false)
createdAt DateTime @default(now())
updatedAt DateTime @updatedAt

// * one user to many posts relation
author User @relation(fields: [authorId], references: [id])
authorId String
}

Note: uuid is of type String, autoincrement is of type Int

Enums

• define a custom enum type in your schema

enum Role {
  USER
  ADMIN
}

model User {
  id String @id @default(uuid())
  role Role @default(USER)
}

Note: Enums are useful for determining the role of a user, or the status of a post (draft, published, etc...)

CRUD Operations

CREATE

// * CREATE
const createUser = await prisma.user.create({
  data: {
    name: 'Pam',
    email: '[email protected]',
    age: 26,

    // * Create a userPreference object at the same time. (relation)
    userPreference: {
      create: {
        emailUpdates: true,
      },
    },
  },

  // * Include the userPreference object in the response
  // include: {
  //   userPreference: true,
  // },

  // * Only show the name and the id of userPreference in the response
  select: {
    name: true,
    userPreference: { select: { id: true } },
  },
})

const createUsers = await prisma.user.createMany({
  data: [
    {
      name: 'Michael',
      email: '[email protected]',
      age: 41,
    },
    {
      name: 'Dwight',
      email: '[email protected]',
      age: 35,
    },
  ],

  // ? You can't use include or select with createMany
})

UPDATE

// * UPDATE
// Update One
const updateOne = await prisma.user.update({
  where: {
    email: '[email protected]',
  },

  data: {
    age: {
      increment: 1, // ? increment, decrement, multiply, divide, append, prepend, delete, remove, disconnect, connect, set
    },
  },
})

// Update Many
const updateMany = await prisma.user.updateMany({
  where: {
    age: { gt: 40 },
  },

  data: {
    email: '[email protected]',
  },
})

CONNECT, DISCONNECT, SET

// * CONNECT, DISCONNECT, SET
const connect = await prisma.user.update({
  where: {
    email: '[email protected]',
  },

  data: {
    userPreference: {
      connect: {
        id: '9c7c2634-5cab-428d-8ca8-0db26bc3c684', // ? userPreferenceId from pam
      },
    },
  },
})

const disconnect = await prisma.user.update({
  where: {
    email: '[email protected]',
  },

  data: {
    userPreference: {
      disconnect: true, // ? now pam's userPreference is null
    },
  },
})

DELETE

// * DELETE
// * delete all
const deleteAll = await prisma.user.deleteMany()

// * delete many that match a condition
const deleteAllUsersAged40Plus = await prisma.user.deleteMany({
  where: {
    age: { gt: 40 },
  },
})

// * delete one
// You need a unique identifier to delete one (you can setup a unique identifier in the schema.prisma file by adding @unique to the field)
const deleteOne = await prisma.user.delete({
  where: {
    email: '[email protected]',
  },
})

READ

// * READ
// * find all users
const findUsers = await prisma.user.findMany()

// * find one user by an unique field (email)
const findUser = await prisma.user.findUnique({
  where: {
    email: '[email protected]',
  },
})

// * find user by multiple unique fields that we specified
// ? @@unique([age, name])
const findUserByMultipleUniqueFields = await prisma.user.findUnique({
  where: {
    age_name: {
      age: 26,
      name: 'Pam',
    },
  },
})

// * find users, sort and limit results
const findSortAndLimitResults = await prisma.user.findMany({
  take: 2, // limit
  skip: 1, // skip
  orderBy: {
    age: 'desc', // sort
  },
})

// ? findFirst - find a user by any field that is not unique
// ? distinct - return only distinct results (only first occurence of each result with a particular field)

FILTERS

// * FILTERS
// * not
const notFilter = await prisma.user.findMany({
  where: {
    name: { not: 'Pam' },
  },
})

// * in, notIn
const inFilter = await prisma.user.findMany({
  where: {
    name: { in: ['Pam', 'Dwight'] },
  },
})

// * lt, lte, gt, gte
const ltFilter = await prisma.user.findMany({
  where: {
    age: { lt: 30 },
  },
})

// * contains, startsWith, endsWith
const containsFilter = await prisma.user.findMany({
  where: {
    name: { contains: 'a' },
  },
})

// * AND, OR, NOT
const andFilter = await prisma.user.findMany({
  where: {
    AND: [{ name: 'Pam' }, { age: { lt: 30 } }],
  },
})

// ARRAY FILTERING
// * some, none, every
// ! hypothetical example
// const someFilter = await prisma.user.findMany({
//   where: {
//     posts: {
//       some: {
//         title: 'Hello World',
//       },
//     },
//   },
// })

Resources

• Prisma Docs
• Prisma Quick Start
• Prisma Playground

License

• MIT

 

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