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Node.js - how to connect with PostgreSQL
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In this article, we would like to show you how to use PostgreSQL in Node.js.
Step 1 - Install the node-postgres module in your Node project.
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npm install pgStep 2 - Import the pg module by using require and create a connection with the PostgreSQL database.
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const { Client } = require('pg');2
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const client = new Client({4
host: '127.0.0.1',5
user: 'postgres',6
database: 'database_name',7
password: 'password',8
port: 5432,9
});10
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const execute = async () => {12
try {13
await client.connect(); // gets connection with database14
console.log('database connected'); // sends queries15
} catch (error) {16
console.log(error.stack);17
} finally {18
await client.end(); // closes connection 19
}20
};21
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execute();That's it, you've been connected and from now on you can query your database.
- with async/await
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const { Client } = require('pg');2
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const client = new Client({4
host: '127.0.0.1',5
user: 'postgres',6
database: 'my_database',7
password: 'password',8
port: 5432,9
});10
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const execute = async () => {12
try {13
await client.connect(); // gets connection14
const response = await client.query('SELECT * FROM users'); // sends queries15
console.log(response.rows);16
} catch (error) {17
console.log(error.stack);18
} finally {19
await client.end(); // closes connection 20
}21
};22
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execute();- with promises
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const { Client } = require('pg');2
3
const client = new Client({4
host: '127.0.0.1',5
user: 'postgres',6
database: 'database_name',7
password: 'password',8
port: 5432,9
});10
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client12
.connect() // gets connection13
.then(() => console.log('database connected'))14
.catch((error) => console.error('connection error', error.stack))15
.then(() => client.query('SELECT * FROM users')) // sends queries16
.then((result) => console.log(JSON.stringify(result.rows, null, 4)))17
.catch((error) => console.error('query error', error.stack))18
.finally(() => client.end()); // closes connection 