title: How get value from URL
body: <p>I want to get the value from the URL to choose data from the database by ID. I want the value for the id.</p>
  <p>For example, if I were to open <code>www.example.com/index.php?id=12</code>.
  I want to get a value whose id = 12 in the database.</p>
  <p>If I open <code>www.example.com/index.php?id=7</code>.</p>
  <p>I want to get the value whose id = 7 in the database and so on.</p>