Use React Query and database for data backup and disaster recovery

Using React Query and database for data backup and disaster recovery requires specific code examples

In modern web development, data backup and disaster recovery are crucial a part of. Whether to protect user data from accidental deletion or system failure or to be able to quickly restore data to maintain business continuity, backing up and restoring data is essential.

React Query is an excellent data management library that provides powerful data query, caching and update capabilities. Combining React Query and the database, we can easily implement data backup and disaster recovery functions.

The following will introduce how to use React Query and database for data backup and disaster recovery, and give specific code examples.

1. Data backup

1. Configuring database

First, we need to configure a database to store backup data. Common choices include MySQL, MongoDB, etc. Here we take MySQL as an example to illustrate.

First, install MySQL and create a database and backup tables. You can use the following SQL statement:

CREATE DATABASE IF NOT EXISTS backupdb;
USE backupdb;

CREATE TABLE IF NOT EXISTS backup_table (
  id INT PRIMARY KEY AUTO_INCREMENT,
  data TEXT,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

2. Create a React Query query hook

Next, create a React Query query hook in the React application to retrieve data from the database Get backup data. You can use the following code:

import { useQuery } from 'react-query';

const fetchBackupData = async () => {
  const response = await fetch('/api/backupdata');
  const data = await response.json();
  return data;
};

const useBackupData = () => {
  return useQuery('backupData', fetchBackupData);
};

In the above code, we used the useQuery hook to initiate an asynchronous request, and implemented the slave API interface in the fetchBackupData function## The logic of obtaining backup data in #/api/backupdata.

Display backup data

useBackupData hook in the component to display backup data. The specific code is as follows:

import React from 'react';
import { useBackupData } from './hooks/useBackupData';

const BackupData = () => {
  const { isLoading, error, data } = useBackupData();

  if (isLoading) {
    return <div>Loading...</div>;
  }

  if (error) {
    return <div>Error: {error.message}</div>;
  }

  return (
    <div>
      <h1>Backup Data</h1>
      <ul>
        {data.map((item) => (
          <li key={item.id}>{item.data}</li>
        ))}
      </ul>
    </div>
  );
};

export default BackupData;

useBackupData hook in the component to obtain the backup data and display the corresponding UI according to the requested status. When the data is loading, "Loading..." is displayed. When an error occurs in the request, an error message is displayed. When the request is successful, the backup data is displayed.

Create disaster recovery service

const mysql = require('mysql');
const backupdb = mysql.createConnection({
  host: 'localhost',
  user: 'root',
  password: 'password',
  database: 'backupdb',
});

const createBackup = async () => {
  return new Promise((resolve, reject) => {
    backupdb.query('INSERT INTO backup_table (data) SELECT data FROM main_table', (error, results, fields) => {
      if (error) {
        reject(error);
      } else {
        resolve(results);
      }
    });
  });
};

const backupOnChange = () => {
  const maindb = mysql.createConnection({
    host: 'localhost',
    user: 'root',
    password: 'password',
    database: 'maindb',
    multipleStatements: true,
  });

  maindb.query('SELECT @dummy := 0;');

  maindb.on('change', () => {
    createBackup()
      .then(() => {
        console.log('Backup created successfully');
      })
      .catch((error) => {
        console.error('Failed to create backup:', error);
      });
  });
};

backupOnChange();

backupdb, Then a createBackup function is defined to insert data from main_table into backup_table. Then we created a MySQL connection to maindb and used the change event to monitor changes in data in the database. When the data changes, the createBackup function is triggered. .

Front-end notification disaster recovery service

import { useMutation, useQueryClient } from 'react-query';

const notifyBackupService = async () => {
  const response = await fetch('/api/notifybackup', { method: 'POST' });
  const data = await response.json();
  return data;
};

const BackupData = () => {
  const queryClient = useQueryClient();
  const { mutate } = useMutation(notifyBackupService, {
    onSuccess: () => {
      queryClient.invalidateQueries('backupData');
      console.log('Backup service notified');
    },
    onError: (error) => {
      console.error('Failed to notify backup service:', error);
    },
  });

  return (
    <div>
      <h1>Backup Data</h1>
      <button onClick={() => mutate()}>Notify Backup Service</button>
    </div>
  );
};

useMutation hook to define a notifyBackupService function, using Notify disaster recovery services. In the option parameters of the useMutation hook, we use the onSuccess callback function to refresh the backup data query and print a success notification message; we use the onError callback function to Handles notification failures and prints an error message. At the same time, we added a button to the component. Clicking the button will trigger the notifyBackupService function to notify the disaster recovery service.

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