React Native Prisma

A Prisma engine adaptation for React Native. Please note that this is a Preview Feature

Installation

npm i --save --save-exact @prisma/client@5.14.0-dev.26 @prisma/react-native@5.14.0-dev.26 react-native-quick-base64
npx expo prebuild --clean

Bare react native projects

For bare project you will need to modify the building process to run a couple of scripts that take care of bundling the migrations you generate inside the final app bundle.

iOS

Go into XCode → Build Phases → Bundle React Native Code and images and modify it so that it looks like this:

set -e

WITH_ENVIRONMENT="../node_modules/react-native/scripts/xcode/with-environment.sh"
REACT_NATIVE_XCODE="../node_modules/react-native/scripts/react-native-xcode.sh"
PRISMA_MIGRATIONS="../node_modules/@prisma/react-native/copy-migrations.sh" # Add this

/bin/sh -c "$WITH_ENVIRONMENT $PRISMA_MIGRATIONS $REACT_NATIVE_XCODE" # Add it to the list of running scripts

Android

For Android you need to modify your apps app/Build.gradle. Add the following at the top of the file.

apply from: "../../node_modules/@prisma/react-native/react-native-prisma.gradle"

Expo

For expo this process is automated into prebuild. Modify your app.json by adding the react-native-prisma plugin.

{
  "expo": {
    // ... The rest of your expo config
    "plugins": ["@prisma/react-native"]
  }
}

Activate preview feature

React Native support is currently a preview feature and has to be activated in your schema.prisma file:

generator client {
  provider = "prisma-client-js"
  previewFeatures = ["reactNative"]
}

datasource db {
  provider = "sqlite"
  url      = "file:./app.db"
}

// Your data model

model User {
  id           Int     @id @default(autoincrement())
  name         String
}

you can now generate the Prisma Client like this:

npx prisma@5.14.0-dev.26 generate

Reactive queries

This package contains an extension to the prisma client that allows you to use reactive queries. Use at your own convinience and care since it might introduce large re-renders in your app.

import { PrismaClient } from '@prisma/client/react-native';
import { reactiveHooksExtension } from '@prisma/react-native';

const baseClient = new PrismaClient();

export const extendedClient = baseClient.$extends(reactiveHooksExtension);

Then in your React component you can use the hook:

import { Text } from 'react-native';
import { extendedClient } from './myDbModule';

export default function App {

  // Will automatically re-render the component with new data
  const users = extendedClient.user.useFindMany();

  return (
    <Text>{ users }</Text>
  )
}

Bare in mind, for the reactive queries to work you have to use the extended client to modify the data:

extendedClient.user.create({ ...userData });

There are several hooks you can use for your reactive queries:

useFindMany();
useFindFirst();
useFindUnique();

Non hook reactive queries

It is also possible to use callbacks for this queries in case you are not using hooks, but you still want to get notified when data changes

import { PrismaClient } from '@prisma/client/react-native';
import { reactiveQueriesExtension } from '@prisma/react-native';

const baseClient = new PrismaClient();

export const extendedClient = baseClient.$extends(reactiveQueriesExtension);

Applying migrations

On application start you need to run the migrations to make sure the database is in a consistent state with your prisma generated client:

import '@prisma/react-native';
import { PrismaClient } from '@prisma/client/react-native';

const basePrisma = new PrismaClient();

async function initializeDb() {
  try {
    basePrisma.$applyPendingMigrations();
  } catch (e) {
    console.error(`failed to apply migrations: ${e}`);
    throw new Error(
      'Applying migrations failed, your app is now in an inconsistent state. We cannot guarantee safety, it is now your responsability to reset the database or tell the user to re-install the app'
    );
  }
}

Care must be taken to ensure migrations will always succeed. Migrations will be executed on the users device at runtime, and if they fail to run, your application will most likely be unable to work correctly. In such a situation, the only option for the user might be to delete all app data and start over.