Simple TypeScript Script Example

This example shows how to use Prisma Client in a simple TypeScript script to read and write data in a SQLite database. You can find the database file with some dummy data at ./prisma/dev.db.

Getting started

1. Download example and install dependencies

Download this example:

npx try-prisma@latest --template typescript/script

Install npm dependencies:

cd script
npm install

Alternative: Clone the entire repo

Clone this repository:

git clone git@github.com:prisma/prisma-examples.git --depth=1

Install npm dependencies:

cd prisma-examples/typescript/script
npm install

2. Create the database

Run the following command to create your SQLite database file. This also creates the User and Post tables that are defined in prisma/schema.prisma:

npx prisma migrate dev --name init

3. Run the script

Execute the script with this command:

npm run dev

Evolving the app

Evolving the application typically requires two steps:

1. Migrate your database using Prisma Migrate
2. Update your application code

For the following example scenario, assume you want to add a "profile" feature to the app where users can create a profile and write a short bio about themselves.

1. Migrate your database using Prisma Migrate

The first step is to add a new table, e.g. called Profile, to the database. You can do this by adding a new model to your Prisma schema file file and then running a migration afterwards:

// schema.prisma

model Post {
  id        Int     @default(autoincrement()) @id
  title     String
  content   String?
  published Boolean @default(false)
  author    User?   @relation(fields: [authorId], references: [id])
  authorId  Int
}

model User {
  id      Int      @default(autoincrement()) @id
  name    String?
  email   String   @unique
  posts   Post[]
+ profile Profile?
}

+model Profile {
+  id     Int     @default(autoincrement()) @id
+  bio    String?
+  userId Int     @unique
+  user   User    @relation(fields: [userId], references: [id])
+}

Once you've updated your data model, you can execute the changes against your database with the following command:

npx prisma migrate dev

2. Update your application code

You can now use your PrismaClient instance to perform operations against the new Profile table. Here are some examples:

Create a new profile for an existing user

const profile = await prisma.profile.create({
  data: {
    bio: "Hello World",
    user: {
      connect: { email: "alice@prisma.io" },
    },
  },
});

Create a new user with a new profile

const user = await prisma.user.create({
  data: {
    email: "john@prisma.io",
    name: "John",
    profile: {
      create: {
        bio: "Hello World",
      },
    },
  },
});

Update the profile of an existing user

const userWithUpdatedProfile = await prisma.user.update({
  where: { email: "alice@prisma.io" },
  data: {
    profile: {
      update: {
        bio: "Hello Friends",
      },
    },
  },
});

Switch to another database (e.g. PostgreSQL, MySQL, SQL Server, MongoDB)

If you want to try this example with another database than SQLite, you can adjust the the database connection in prisma/schema.prisma by reconfiguring the datasource block.

Learn more about the different connection configurations in the docs.

Expand for an overview of example configurations with different databases

PostgreSQL

For PostgreSQL, the connection URL has the following structure:

datasource db {
  provider = "postgresql"
  url      = "postgresql://USER:PASSWORD@HOST:PORT/DATABASE?schema=SCHEMA"
}

Here is an example connection string with a local PostgreSQL database:

datasource db {
  provider = "postgresql"
  url      = "postgresql://janedoe:mypassword@localhost:5432/notesapi?schema=public"
}

MySQL

For MySQL, the connection URL has the following structure:

datasource db {
  provider = "mysql"
  url      = "mysql://USER:PASSWORD@HOST:PORT/DATABASE"
}

Here is an example connection string with a local MySQL database:

datasource db {
  provider = "mysql"
  url      = "mysql://janedoe:mypassword@localhost:3306/notesapi"
}

Microsoft SQL Server

Here is an example connection string with a local Microsoft SQL Server database:

datasource db {
  provider = "sqlserver"
  url      = "sqlserver://localhost:1433;initial catalog=sample;user=sa;password=mypassword;"
}

MongoDB

Here is an example connection string with a local MongoDB database:

datasource db {
  provider = "mongodb"
  url      = "mongodb://USERNAME:PASSWORD@HOST/DATABASE?authSource=admin&retryWrites=true&w=majority"
}

Next steps

• Check out the Prisma docs
• Share your feedback on the Prisma Discord
• Create issues and ask questions on GitHub