How to Use React Query for Efficient Data Fetching

Introduction

React Query makes it easy to get data from a server. It helps you fetch, cache, and update data without much code. In this article, we will explore how to set up React Query, its key features, and tips for using it to make your apps faster and smarter. Let's dive in!

What is React Query?

React Query is a powerful library for managing server state in your React applications. Instead of writing complex and repetitive code for data fetching, React Query simplifies the process. It handles caching, background updates, and syncing data, which lets you focus on building your app.

Setting Up React Query

To start using React Query, you need to install it first. You can do this using npm or yarn.

npm install react-query

yarn add react-query

Basic Usage

Once you have installed React Query, you need to set it up in your app. Wrap your main component with the QueryClientProvider. This provider gives you access to all the features of React Query.

import { QueryClient, QueryClientProvider } from 'react-query';

const queryClient = new QueryClient();

function App() {
  return (
    
      {/* Your components go here */}
    
  );
}

Fetching Data

To fetch data, you can use the useQuery hook. This hook takes two arguments: a unique key and a function that fetches the data. Here's a simple example:

import { useQuery } from 'react-query';

function fetchUser() {
  return fetch('https://api.example.com/user').then(response => response.json());
}

function User() {
  const { data, error, isLoading } = useQuery('user', fetchUser);
  
  if (isLoading) return Loading...;
  if (error) return Error fetching data;

  return {data.name};
}

Understanding the Response

The response from useQuery gives you three important states:

isLoading: When true, it means the data is still loading.
error: If there is an error fetching data, this will contain the error information.
data: This is where your fetched data will be stored once it loads successfully.

Caching and Background Updates

One of the great things about React Query is its caching abilities. When you fetch data, React Query stores it. If you try to fetch the same data again, it uses the cached version first, making your app faster. Plus, it will automatically update the data in the background.

You can control how long to cache data by setting staleTime and cacheTime:

const { data } = useQuery('user', fetchUser, {
  staleTime: 10000, // 10 seconds
  cacheTime: 300000, // 5 minutes
});

Updating Data

Updating data is straightforward with the useMutation hook. This hook is used when you need to create, update, or delete records. Here's an example of updating user data:

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

function UpdateUser() {
  const queryClient = useQueryClient();

  const mutation = useMutation(updateUser, {
    onSuccess: () => {
      // Invalidate and refetch
      queryClient.invalidateQueries('user');
    },
  });

  return (
    
  );
}

Conclusion

React Query offers a simple way to manage data fetching in your applications. By using its hooks, you can fetch, cache, and update data efficiently. This makes your apps not only faster but also more responsive. Start using React Query today to enhance your development experience!