Build a Simple CRUD Node.js App with CockroachDB and Knex.js

This tutorial shows you how build a simple Node.js application with CockroachDB and Knex.js.

Step 1. Start CockroachDB

Create a free cluster

  1. If you haven't already, sign up for a CockroachDB Cloud account.
  2. Log in to your CockroachDB Cloud account.
  3. On the Clusters page, click Create Cluster.
  4. On the Create your cluster page, select Serverless.

    Unless you change your monthly budget, this cluster will be free forever.

  5. Click Create cluster.

    Your cluster will be created in a few seconds and the Create SQL user dialog will display.

Create a SQL user

The Create SQL user dialog allows you to create a new SQL user and password.

  1. Enter a username in the SQL user field or use the one provided by default.
  2. Click Generate & save password.
  3. Copy the generated password and save it in a secure location.
  4. Click Next.

    Currently, all new users are created with full privileges. For more information and to change the default settings, see Granting privileges and Using roles.

Get the connection string

The Connect to cluster dialog shows information about how to connect to your cluster.

  1. Select General connection string from the Select option dropdown.
  2. Open the General connection string section, then copy the connection string provided and save it in a secure location.

    The sample application used in this tutorial uses system CA certificates for server certificate verification, so you can skip the Download CA Cert instructions.

    Note:

    The connection string is pre-populated with your username, password, cluster name, and other details. Your password, in particular, will be provided only once. Save it in a secure place (Cockroach Labs recommends a password manager) to connect to your cluster in the future. If you forget your password, you can reset it by going to the SQL Users page.

  1. If you haven't already, download the CockroachDB binary.
  2. Run the cockroach start-single-node command:

    icon/buttons/copy
    $ cockroach start-single-node --advertise-addr 'localhost' --insecure
    

    This starts an insecure, single-node cluster.

  3. Take note of the following connection information in the SQL shell welcome text:

    CockroachDB node starting at 2021-08-30 17:25:30.06524 +0000 UTC (took 4.3s)
    build:               CCL v21.1.6 @ 2021/07/20 15:33:43 (go1.15.11)
    webui:               http://localhost:8080
    sql:                 postgresql://root@localhost:26257?sslmode=disable
    

    You'll use the sql connection string to connect to the cluster later in this tutorial.

Warning:

The --insecure flag used in this tutorial is intended for non-production testing only. To run CockroachDB in production, use a secure cluster instead.

Step 2. Get the code

Clone the code's GitHub repo:

icon/buttons/copy
$ git clone https://github.com/cockroachlabs/example-app-node-knex

Step 3. Run the code

  1. Set the DATABASE_URL environment variable to the connection string:

    icon/buttons/copy
    $ export DATABASE_URL="postgresql://root@localhost:26257?sslmode=disable"
    
    icon/buttons/copy
    $ export DATABASE_URL="<connection-string>"
    

    Where <connection-string> is the connection string you obtained from the CockroachDB Cloud Console.

    The app uses the connection string saved to the DATABASE_URL environment variable to connect to your cluster and execute the code.

  2. Install the app requirements:

    icon/buttons/copy
    $ npm install
    
  3. Run the app:

    icon/buttons/copy
    $ npm run run
    

    The output should look like this:

    Initializing accounts table...
    New account balances:
    { id: 'bc0f7136-7103-4dc4-88fc-102d5bbd312f', balance: '1000' }
    { id: '35bde7d0-29c9-4277-a117-3eb80c85ae16', balance: '250' }
    { id: '18cc1b2d-be61-4a8d-942c-480f5a6bc207', balance: '0' }
    Transferring funds...
    New account balances:
    { id: 'bc0f7136-7103-4dc4-88fc-102d5bbd312f', balance: '900' }
    { id: '35bde7d0-29c9-4277-a117-3eb80c85ae16', balance: '350' }
    { id: '18cc1b2d-be61-4a8d-942c-480f5a6bc207', balance: '0' }
    Deleting a row...
    New account balances:
    { id: 'bc0f7136-7103-4dc4-88fc-102d5bbd312f', balance: '900' }
    { id: '18cc1b2d-be61-4a8d-942c-480f5a6bc207', balance: '0' }
    

What's next?

You might also be interested in the following pages:

YesYes NoNo