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.
examples-orms
repository.Before You Begin
Make sure you have already installed CockroachDB.
Step 1. 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 2. Start a single-node cluster
For the purpose of this tutorial, you need only one CockroachDB node running in insecure mode:
$ cockroach start \
--insecure \
--store=hello-1 \
--host=localhost
Step 3. Create a user
In a new terminal, as the root
user, use the cockroach user
command to create a new user, maxroach
.
$ cockroach user set maxroach --insecure
Step 4. Create a database and grant privileges
As the root
user, use the built-in SQL client to create a bank
database.
$ cockroach sql --insecure -e 'CREATE DATABASE bank'
Then grant privileges to the maxroach
user.
$ cockroach sql --insecure -e 'GRANT ALL ON DATABASE bank TO maxroach'
Step 5. Run the Node.js 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.
Copy the code or download it directly.
var Sequelize = require('sequelize-cockroachdb');
// Connect to CockroachDB through Sequelize.
var sequelize = new Sequelize('bank', 'maxroach', '', {
dialect: 'postgres',
port: 26257,
logging: false
});
// Define the Account model for the "accounts" table.
var 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);
});
Then run the code:
$ node sequelize-basic-sample.js
The output should be:
1 1000
2 250
To verify that the table and rows were created successfully, you can again use the built-in SQL client:
$ cockroach sql --insecure -e 'SHOW TABLES' --database=bank
+----------+
| Table |
+----------+
| accounts |
+----------+
(1 row)
$ cockroach sql --insecure -e 'SELECT id, balance FROM accounts' --database=bank
+----+---------+
| id | balance |
+----+---------+
| 1 | 1000 |
| 2 | 250 |
+----+---------+
(2 rows)
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 using a local cluster to explore the following core CockroachDB features: