Seeding
Seeding allows you to consistently re-create the same data in your database and can be used to:
- Populate your database with data that is required for your application to start, such as a default language or currency.
- Provide basic data for validating and using your application in a development environment. This is particularly useful if you are using Prisma Migrate, which sometimes requires resetting your development database.
https://www.youtube.com/embed/mulzjQ4pZaA
Prisma ORM's integrated seeding functionality expects a command in the "seed" key in the migrations object of your prisma.config.ts. This can be any command; prisma db seed executes it as given. In this guide and as a default, we recommend writing a seed script inside your project's prisma/ folder and starting it with the command.
import "dotenv/config";
import { defineConfig, env } from "prisma/config";
export default defineConfig({
schema: "prisma/schema.prisma",
migrations: {
path: "prisma/migrations",
seed: "tsx prisma/seed.ts",
},
datasource: {
url: env("DATABASE_URL"),
},
});Database seeding happens when you run prisma db seed. With prisma db seed, you decide when to invoke the seed command. It can be useful for a test setup or to prepare a new development environment, for example.
Here we suggest some specific seed scripts for different situations. You are free to customize these in any way, but can also use them as presented here:
- Create a new file named
seed.ts. This can be placed anywhere within your project's folder structure. The example below places it in the/prismafolder. - In the
seed.tsfile, import Prisma Client, initialize it and create some records. As an example, take the following Prisma schema with aUserandPostmodel:
model User {
id Int @id @default(autoincrement())
email String @unique
name String
posts Post[]
}
model Post {
id Int @id @default(autoincrement())
title String
content String
published Boolean
user User @relation(fields: [userId], references: [id])
userId Int
}Create some new users and posts in your prisma/seed.ts file:
import "dotenv/config";
import { Pool } from "pg";
import { PrismaPg } from "@prisma/adapter-pg";
import { PrismaClient } from "../prisma/generated/client";
const connectionString = `${process.env.DATABASE_URL}`;
const pool = new Pool({ connectionString });
const adapter = new PrismaPg(pool);
const prisma = new PrismaClient({ adapter });
async function main() {
const alice = await prisma.user.upsert({
where: { email: "alice@prisma.io" },
update: {},
create: {
email: "alice@prisma.io",
name: "Alice",
posts: {
create: {
title: "Check out Prisma with Next.js",
content: "https://www.prisma.io/nextjs",
published: true,
},
},
},
});
const bob = await prisma.user.upsert({
where: { email: "bob@prisma.io" },
update: {},
create: {
email: "bob@prisma.io",
name: "Bob",
posts: {
create: [
{
title: "Follow Prisma on Twitter",
content: "https://twitter.com/prisma",
published: true,
},
{
title: "Follow Nexus on Twitter",
content: "https://twitter.com/nexusgql",
published: true,
},
],
},
},
});
console.log({ alice, bob });
}
main()
.then(async () => {
await prisma.$disconnect();
await pool.end();
})
.catch(async (e) => {
console.error(e);
await prisma.$disconnect();
await pool.end();
process.exit(1);
});- Add
typescript,tsx,@types/node,@prisma/adapter-pg,pg,@types/pganddotenvdevelopment dependencies:
bun add --dev typescript tsx @types/node @prisma/adapter-pg pg @types/pg dotenvpnpm add -D typescript tsx @types/node @prisma/adapter-pg pg @types/pg dotenvyarn add --dev typescript tsx @types/node @prisma/adapter-pg pg @types/pg dotenvnpm install -D typescript tsx @types/node @prisma/adapter-pg pg @types/pg dotenv- Add the
seedfield to yourprisma.config.tsfile:
import "dotenv/config";
import { defineConfig, env } from "prisma/config";
export default defineConfig({
schema: "prisma/schema.prisma",
migrations: {
path: "prisma/migrations",
seed: "tsx prisma/seed.ts",
},
datasource: {
url: env("DATABASE_URL"),
},
});- To seed the database, run the
db seedCLI command:
bunx prisma db seedpnpm prisma db seedyarn prisma db seednpx prisma db seedWe're using TypeScript here, but it's possible to do the same thing in vanilla JavaScript. The same steps would be followed, expect with a prisma/seed.js file (without types), and calling node prisma/seed.js instead of tsx.
We're using TypeScript here, but it's possible to do the same thing in vanilla JavaScript. The same steps would be followed, expect with a prisma/seed.js file (without types), and calling node prisma/seed.js instead of tsx.
You can also make use of raw SQL queries in order to seed the database with data.
While you can use a plain-text .sql file (such as a data dump) for that, it is often easier to place those raw queries, if they're of short size, into the seed.js file because it saves you the hassle of working out database connection strings and creating a dependency on a binary like psql.
To seed additional data to the schema.prisma above, add the following to the seed.js (or seed.ts) file:
async function rawSql() {
const result =
await prisma.$executeRaw`INSERT INTO "User" ("id", "email", "name") VALUES (3, 'foo@example.com', 'Foo') ON CONFLICT DO NOTHING;`;
console.log({ result });
}and chain this function to the promise calls, such as the following change towards the end of the file:
main()
.then(rawSql)
.then(async () => {
await prisma.$disconnect();
await pool.end();
})
.catch(async (e) => {
console.error(e);
await prisma.$disconnect();
await pool.end();
process.exit(1);
});Seeding your database via any language (with a Bash script)
Section titled “Seeding your database via any language (with a Bash script)”In addition to TypeScript and JavaScript, you can also use a Bash script (seed.sh) to seed your database in another language such as Go, or plain SQL.
The following example runs a Go script in the same folder as seed.sh:
#!/bin/sh
# -e Exit immediately when a command returns a non-zero status.
# -x Print commands before they are executed
set -ex
# Seeding command go
run ./seed/The following example uses psql to run a SQL script in the same folder as seed.sh:
#!/bin/sh
# -e Exit immediately when a command returns a non-zero status.
# -x Print commands before they are executed
set -ex
# Seeding command
psql file.sqlprisma db seed allows you to define custom arguments in your seed file that you can pass to the prisma db seed command. For example, you could define your own arguments to seed different data for different environments or partially seeding data in some tables.
Here is an example seed file that defines a custom argument to seed different data in different environments:
import { parseArgs } from "node:util";
const options = {
environment: { type: "string" },
};
async function main() {
const {
values: { environment },
} = parseArgs({ options });
switch (environment) {
case "development":
/** data for your development */
break;
case "test":
/** data for your test environment */
break;
default:
break;
}
}
main()
.then(async () => {
await prisma.$disconnect();
})
.catch(async (e) => {
console.error(e);
await prisma.$disconnect();
process.exit(1);
});You can then provide the environment argument when using prisma db seed by adding a delimiter — -- —, followed by your custom arguments:
bunx prisma db seed -- --environment developmentpnpm prisma db seed -- --environment developmentyarn prisma db seed -- --environment developmentnpx prisma db seed -- --environment developmentHere's a non-exhaustive list of other tools you can integrate with Prisma ORM in your development workflow to seed your database: