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Build a Node.js App with CockroachDB
Learn how to use CockroachDB from a simple Node.js application with the Node.js pg driver.
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This tutorial shows you how build a simple Node.js application with CockroachDB using a PostgreSQL-compatible driver or ORM. We've tested and can recommend the Node.js pg driver and the Sequelize ORM, so those are featured here.

Before You Begin

Make sure you have already installed CockroachDB.

Step 1. Install Node.js packages

To let your application communicate with CockroachDB, install the Node.js pg driver:

{% include copy-clipboard.html %}

$ npm install pg

The example app on this page also requires async:

{% include copy-clipboard.html %}

$ npm install async

{% include {{ page.version.version }}/app/common-steps.md %}

Step 5. Run the Node.js code

Now that you have a database and a user, you'll run code to create a table and insert some rows, and then you'll run code to read and update values as an atomic transaction.

Basic Statements

First, use the following code to connect as the maxroach user and execute some basic SQL statements, creating a table, inserting rows, and reading and printing the rows.

Download the basic-sample.js file, or create the file yourself and copy the code into it.

{% include copy-clipboard.html %}

{% include {{ page.version.version }}/app/basic-sample.js %}

Then run the code:

{% include copy-clipboard.html %}

$ node basic-sample.js

The output should be:

Initial balances:
{ id: '1', balance: '1000' }
{ id: '2', balance: '250' }

Transaction (with retry logic)

Next, use the following code to again connect as the maxroach user but this time execute a batch of statements as an atomic transaction to transfer funds from one account to another and then read the updated values, where all included statements are either committed or aborted.

Download the txn-sample.js file, or create the file yourself and copy the code into it.

{{site.data.alerts.callout_info}}With the default SERIALIZABLE isolation level, CockroachDB may require the client to retry a transaction in case of read/write contention. CockroachDB provides a generic retry function that runs inside a transaction and retries it as needed. You can copy and paste the retry function from here into your code.{{site.data.alerts.end}}

{% include copy-clipboard.html %}

{% include {{ page.version.version }}/app/txn-sample.js %}

Then run the code:

{% include copy-clipboard.html %}

$ node txn-sample.js

The output should be:

Balances after transfer:
{ id: '1', balance: '900' }
{ id: '2', balance: '350' }

However, if you want to verify that funds were transferred from one account to another, use the built-in SQL client:

{% include copy-clipboard.html %}

$ cockroach sql --insecure -e 'SELECT id, balance FROM accounts' --database=bank
+----+---------+
| id | balance |
+----+---------+
|  1 |     900 |
|  2 |     350 |
+----+---------+
(2 rows)

What's Next?

Read more about using the Node.js pg driver.

You might also be interested in using a local cluster to explore the following core CockroachDB features: