next.js/test/integration/basic/pages/nav/querystring.js

import React from 'react'
import Link from 'next/link'

export default class AsyncProps extends React.Component {
  static async getInitialProps ({ query: { id = 0 } }) {
    return { id }
  }

  render () {
    return (
      <div className='nav-querystring'>
        <Link href={`/nav/querystring?id=${parseInt(this.props.id) + 1}`}>
          <a id='next-id-link'>Click here</a>
        </Link>
        <Link href='/nav/querystring'>
          <a id='main-page'>Click here</a>
        </Link>
        <p className={`nav-id-${this.props.id}`}>{this.props.id}</p>
      </div>
    )
  }
}