This tutorial shows you how build a simple Node.js application with CockroachDB and the Sequelize ORM.
We have tested the Sequelize ORM enough to claim beta-level support. If you encounter problems, please open an issue with details to help us make progress toward full support.
For a more realistic use of Sequelize with CockroachDB, see our examples-orms
repository.
Step 1. Start CockroachDB
- If you haven't already, download the CockroachDB binary.
Run the
cockroach demo
command:$ cockroach demo \ --empty
This starts a temporary, in-memory cluster and opens an interactive SQL shell to the cluster.
Take note of the
(sql/tcp)
connection string in the SQL shell welcome text:# Connection parameters: # (console) http://127.0.0.1:61009 # (sql) postgres://root:admin@?host=%2Fvar%2Ffolders%2Fk1%2Fr048yqpd7_9337rgxm9vb_gw0000gn%2FT%2Fdemo255013852&port=26257 # (sql/tcp) postgres://root:admin@127.0.0.1:61011?sslmode=require
You will use it in your application code later.
Step 2. Create a database
In the SQL shell, create the
bank
database that your application will use:> CREATE DATABASE bank;
Create a SQL user for your app:
> CREATE USER <username> WITH PASSWORD <password>;
Take note of the username and password. You will use it in your application code later.
Give the user the necessary permissions:
> GRANT ALL ON DATABASE bank TO <username>;
Step 3. Install the Sequelize ORM
To install Sequelize, as well as a CockroachDB Node.js package that accounts for some minor differences between CockroachDB and PostgreSQL, run the following command:
$ npm install sequelize sequelize-cockroachdb
Step 4. Get the code
Download the sample code directly, or clone the code's GitHub repository.
Step 5. Update the connection parameters
Open app.js
, and edit the connection configuration parameters:
- Replace the value for
username
with the user you created earlier. - Replace the value for
password
with the password you created for your user. - Replace the value for
port
with the port to your cluster.
At the top of the file, uncomment the
const fs = require('fs');
line.This line imports the
fs
Node module, which enables you to read in the CA cert that you downloaded from the CockroachDB Cloud Console.Replace the value for
username
with the user you created earlier.Replace the value for
password
with the password you created for your user.Replace the value for
host
with the name of the CockroachDB Serverless host (e.g.,host: 'free-tier.gcp-us-central1.cockroachlabs.cloud'
).Replace the value for
port
with the port to your cluster.Replace the value for
database
with the database that you created earlier, suffixed with the name of the cluster (e.g.,database: '{cluster_name}.bank'
).Remove the
rejectUnauthorized
key-value pair.Uncomment the
ca
key-value pair, and edit thefs.readFileSync('certs/ca.crt').toString()
call to use the path to thecc-ca.crt
file that you downloaded from the CockroachDB Cloud Console.
Step 6. Run the code
The following code uses the Sequelize ORM to map Node.js-specific objects to SQL operations. Specifically, Account.sync({force: true})
creates an accounts
table based on the Account model (or drops and recreates the table if it already exists), Account.bulkCreate([...])
inserts rows into the table, and Account.findAll()
selects from the table so that balances can be printed.
const Sequelize = require("sequelize-cockroachdb");
// Connect to CockroachDB through Sequelize.
const connectionString = process.env.DATABASE_URL
const sequelize = new Sequelize(connectionString, {
dialectOptions: {
application_name: "docs_simplecrud_node-sequelize"
}
});
// Define the Account model for the "accounts" table.
const Account = sequelize.define("accounts", {
id: {
type: Sequelize.INTEGER,
primaryKey: true,
},
balance: {
type: Sequelize.INTEGER,
},
});
// Create the "accounts" table.
Account.sync({
force: true,
})
.then(function () {
// Insert two rows into the "accounts" table.
return Account.bulkCreate([
{
id: 1,
balance: 1000,
},
{
id: 2,
balance: 250,
},
]);
})
.then(function () {
// Retrieve accounts.
return Account.findAll();
})
.then(function (accounts) {
// Print out the balances.
accounts.forEach(function (account) {
console.log(account.id + " " + account.balance);
});
process.exit(0);
})
.catch(function (err) {
console.error("error: " + err.message);
process.exit(1);
});
To run the code:
$ node app.js
The output should be:
1 1000
2 250
What's next?
Read more about using the Sequelize ORM, or check out a more realistic implementation of Sequelize with CockroachDB in our examples-orms
repository.
You might also be interested in the following pages: