Saving WebSockets data in the database using Ethereum
Ethereum’s WebSockets API provides bidirectional communication between client and server in real time. In this article, we’ll look at how to save WebSocket data received from a Binance stream to a database such as MySQL or PostgreSQL.
Prerequisites
- Familiarity with JavaScript, Node.js and Ethereum development
- Setting up an Ethereum base node (e.g. Ethereum Classic or Polygon) and a blockchain explorer (e.g. Etherscan)
- Installation of necessary libraries:
ws,mysql2anddotenv
Step 1: Establish a WebSocket Connection
First you need to connect to Binance stream. You can use the wss://stream.binance.com:9443/ws/btcusdt@trade endpoint to connect to the Bitcoin USDT trade stream.
const WebSocket = require('ws');
const wss = new WebSocket.Server({ port: 9443, secure: true });
Step 2: Handle WebSocket messages
When a message is received from the Binance stream, you will need to process it accordingly. You can use a library such as ws to analyze and process WebSocket messages.
wss.on('connection', (ws) => {
console.log('Client connected');
ws.on('message', (message) => {
const data = JSON.parse(message);
// Process the received data here...
ws.send(JSON.stringify({ type: 'result', data }));
});
ws.on('close', () => {
console.log('Client disconnected');
});
});
Step 3: Save the data to the database
To save WebSocket data to a database, you need an API that supports interaction with your database. We will use the mysql2 library to connect to your MySQL or PostgreSQL database.
const mysql = require('mysql');
const dbConfig = {
host: 'your_host',
user: 'your_user',
password: 'your_password',
database: 'your_database',
};
const connection = mysql.createConnection(dbConfig);
connection.connect((err) => {
if (err) {
console.error('error connection:', err);
return;
}
console.log('connected as id ' + connection.threadId);
// Sending data to the database here...
connection.end();
});
Putting everything together
Here’s a complete example that demonstrates how to save WebSocket data to a MySQL database:
“`javascript
const express = require(‘express’);
const app = express();
const bodyParser = require(‘body-parser’);
const ws = require(‘ws’);
const mysql = require(‘mysql2/promise’);
const dbConfig = {
host: ‘your_host’,
user: ‘your_user’,
password: ‘your_password’,
database: ‘your_database’,
};
// Establish a WebSocket connection
const wss = new WebSocket.Server({ port: 9443, secure: true });
wss.on(‘connection’, (ws) => {
console.log(‘Client connected’);
// Processing incoming messages from the Binance stream
ws.on(‘message’, (message) => {
const data = JSON.parse(message);
// Process the received data here…
// Saving data in the data base
saveDataToDatabase(data);
});
ws.on(‘close’, () => {
console.log(‘Client disconnected’);
});
});
// Function for processing and saving WebSocket messages in the database
async function saveDataToDatabase(data) {
try {
const query = ‘INSERT INTO websocket_data (id, timestamp, data) VALUES (?, ?, ?)’;
const [result] = await connection.execute(query, [
null,
new Date().toISOString(),
JSON.stringify(data),
]);
console.log(‘Inserted into database:’, result);
} catch (err) {
console.error(‘Error inserting into database:’, err);
}
}
app.use(bodyParser.json());
app.listen(3000, () => {
console.