title: Convert PDO fetch in PHP array list
body: <p>There are any way to convert a PDO fetch (only 1 column) in a PHP array? Instead of a foreach loop.
  Example:</p>
  
  <pre><code>"data": [
      {
          "A": "1"
      },
      {
          "A": "2"
      },
      {
          "A": "3"
      }
  ]
  </code></pre>
  
  <p>expected:</p>
  
  <pre><code>"data": [
      "1",
      "2",
      "3"
  ]
  </code></pre>