Cloudflare Docs
D1
Edit this page on GitHub
Set theme to dark (⇧+D)

Get started

This guide will instruct you through:

  • Creating your first database using D1, Cloudflare’s native serverless SQL database.
  • Creating a schema and querying your database via the command-line.
  • Connecting a Cloudflare Worker to your D1 database to query your D1 database programmatically.

​​ Prerequisites

To continue:

  1. Sign up for a Cloudflare account if you have not already.
  2. Install npm.
  3. Install Node.js. Use a Node version manager like Volta or nvm to avoid permission issues and change Node.js versions. Wrangler requires a Node version of 16.17.0 or later.

​​ 1. Log in

Before creating your D1 database, log in with your Cloudflare account by running:

$ npx wrangler login

You will be directed to a web page asking you to log in to the Cloudflare dashboard. After you have logged in, you will be asked if Wrangler can make changes to your Cloudflare account. Scroll down and select Allow to continue.

​​ 2. Create a Worker

You will create a new Worker as the means to query your database.

Create a new project named d1-tutorial by running:

$ npm create cloudflare@latest d1-tutorial

When setting up your d1-tutorial Worker, answer the questions as below:

  • Your directory has been titled d1-tutorial.
  • Choose "Hello World" Worker for the type of application.
  • Select yes to using TypeScript.
  • Select yes to using Git.
  • Select no to deploying.

This will create a new d1-tutorial directory. Your new d1-tutorial directory will include:

  • A "Hello World" Worker at src/index.ts.
  • A wrangler.toml configuration file. wrangler.toml is how your d1-tutorial Worker will access your D1 database.

​​ 3. Create a database

A D1 database is conceptually similar to many other databases: a database may contain one or more tables, the ability to query those tables, and optional indexes. D1 uses the familiar SQL query language (as used by SQLite).

To create your first D1 database, change into the directory you just created for your Workers project:

$ cd d1-tutorial

Run the following wrangler d1 command and give your database a name. In this tutorial, the database will be named prod-d1-tutorial

$ npx wrangler d1 create prod-d1-tutorial
✅ Successfully created DB 'prod-d1-tutorial'
[[d1_databases]]
binding = "DB" # available in your Worker on env.DB
database_name = prod-d1-tutorial"
database_id = "<unique-ID-for-your-database>"

This will create a new D1 database, and output the binding configuration needed in the next step.

​​ 4. Bind your Worker to your D1 database

You must create a binding for your Worker to connect to your D1 database. Bindings allow your Workers to access resources, like D1, on the Cloudflare developer platform. You create bindings by updating your wrangler.toml file.

To bind your D1 database to your Worker, add the following to the end of your wrangler.toml file:

wrangler.toml
[[d1_databases]]
binding = "DB" # available in your Worker on env.DB
database_name = "prod-d1-tutorial"
database_id = "<unique-ID-for-your-database>"

Specifically:

  • The value (string) you set for <BINDING_NAME> will be used to reference this database in your Worker. In this tutorial, name your binding DB.
  • The binding must be a valid JavaScript variable name. For example, binding = "MY_DB" or binding = "productionDB" would both be valid names for the binding.
  • Your binding is available in your Worker at env.<BINDING_NAME> and the D1 client API is exposed on this binding.

You can also bind your D1 database to a Pages Function. For more information, refer to Functions Bindings.

​​ 5. Run a query against your D1 database

​​ Configure your D1 database

With wrangler.toml configured properly, you will set up your database. Use the following example schema.sql file to initialize your database. Copy the following code and save it as a schema.sql file in the d1-tutorial Worker directory you created in step 1:

schema.sql
DROP TABLE IF EXISTS Customers;
CREATE TABLE IF NOT EXISTS Customers (CustomerId INTEGER PRIMARY KEY, CompanyName TEXT, ContactName TEXT);
INSERT INTO Customers (CustomerID, CompanyName, ContactName) VALUES (1, 'Alfreds Futterkiste', 'Maria Anders'), (4, 'Around the Horn', 'Thomas Hardy'), (11, 'Bs Beverages', 'Victoria Ashworth'), (13, 'Bs Beverages', 'Random Name');

You will initialize your database to run and test locally first. Bootstrap your new D1 database by running:

$ npx wrangler d1 execute prod-d1-tutorial --local --file=./schema.sql

Then validate your data is in your database by running:

$ npx wrangler d1 execute prod-d1-tutorial --local --command="SELECT * FROM Customers"

You should see the following output:

🌀 Mapping SQL input into an array of statements
🌀 Executing on local database production-db-backend (5f092302-3fbd-4247-a873-bf1afc5150b) from .wrangler/state/v3/d1:
┌────────────┬─────────────────────┬───────────────────┐
│ CustomerId │ CompanyName │ ContactName │
├────────────┼─────────────────────┼───────────────────┤
│ 1 │ Alfreds Futterkiste │ Maria Anders │
├────────────┼─────────────────────┼───────────────────┤
│ 4 │ Around the Horn │ Thomas Hardy │
├────────────┼─────────────────────┼───────────────────┤
│ 11 │ Bs Beverages │ Victoria Ashworth │
├────────────┼─────────────────────┼───────────────────┤
│ 13 │ Bs Beverages │ Random Name │
└────────────┴─────────────────────┴───────────────────┘

​​ Write queries within your Worker

After you have set up your database, you will run an SQL query from within your Worker.

First, go to your d1-tutorial Worker and open the index.ts file. The index.ts file is where you configure your Worker’s interactions with D1.

Clear the content of index.ts. Paste the following code snippet into your index.ts file:

src/index.ts
export interface Env {
// If you set another name in wrangler.toml as the value for 'binding',
// replace "DB" with the variable name you defined.
DB: D1Database;
}
export default {
async fetch(request: Request, env: Env) {
const { pathname } = new URL(request.url);
if (pathname === "/api/beverages") {
// If you did not use `DB` as your binding name, change it here
const { results } = await env.DB.prepare(
"SELECT * FROM Customers WHERE CompanyName = ?"
)
.bind("Bs Beverages")
.all();
return Response.json(results);
}
return new Response(
"Call /api/beverages to see everyone who works at Bs Beverages"
);
},
};

In the code above, you:

  1. Define a binding to your D1 database in your TypeScript code. This binding matches the binding value you set in wrangler.toml under [[d1_databases]].
  2. Query your database using env.DB.prepare to issue a prepared query with a placeholder (the ? in the query).
  3. Call bind() to safely and securely bind a value to that placeholder. In a real application, you would allow a user to define the CompanyName they want to list results for. Using bind() prevents users from executing arbitrary SQL (known as “SQL injection”) against your application and deleting or otherwise modifying your database.
  4. Execute the query by calling all() to return all rows (or none, if the query returns none).
  5. Return your query results, if any, in JSON format with Response.json(results).

After configuring your Worker, you can test your project locally before you deploy globally.

​​ 6. Develop locally with Wrangler

While in your project directory, test your database locally by running:

$ npx wrangler dev

When you run wrangler dev, Wrangler will give you a URL (most likely localhost:8787) to review your Worker. After you visit the URL Wrangler provides, you will see this message: Call /api/beverages to see everyone who works at Bs Beverages.

To test that your database is running successfully, add /api/beverages to the provided Wrangler URL: for example, localhost:8787/api/beverages. After doing this, you should see your data being displayed in the browser.

​​ 7. Deploy your database

To deploy your Worker to production, you must first repeat the database bootstrapping steps without the --local flag to give your Worker data to read. This will create the database tables and import the data into the production version of your database, running on Cloudflare’s global network.

First, bootstrap your database with the schema.sql file you created in step 4:

$ npx wrangler d1 execute prod-d1-tutorial --file=./schema.sql

Then validate the data is in production by running:

$ npx wrangler d1 execute prod-d1-tutorial --command="SELECT * FROM Customers"

Finally, deploy your Worker to make your project accessible on the Internet. To deploy your Worker, run:

$ npx wrangler deploy
# Outputs: https://d1-tutorial.<YOUR_SUBDOMAIN>.workers.dev

You can now visit the URL for your newly created project to query your live database.

For example, if the URL of your new Worker is d1-tutorial.<YOUR_SUBDOMAIN>.workers.dev, accessing https://d1-tutorial.<YOUR_SUBDOMAIN>.workers.dev/api/beverages will send a request to your Worker that queries your live database directly.

By finishing this tutorial, you have created a D1 database, a Worker to access that database and deployed your project globally.

​​ Next steps

If you have any feature requests or notice any bugs, share your feedback directly with the Cloudflare team by joining the Cloudflare Developers community on Discord.