Retrieving a Single Field from a Table in PDO in PHP

Besides the fetch method, there is a special method fetchColumn, which allows you to get the value of a single column. Let's see what is meant.

First, let's prepare and execute a query. We will specify that we want to select only the name field:

php<?php
  $res = $pdo->prepare('SELECT name FROM users');
  $res->execute();
?>

Let's get the results using the fetch method:

php<?php
  while ($col = $res->fetch()) {
    var_dump($col);
  }
?>

As a result, in each iteration we will see an array consisting of one element - the user's name:

php['name1']
['name2']
['name3']

Now let's apply fetchColumn:

php<?php
  while ($col = $res->fetchColumn()) {
    var_dump($col);
  }
?>

As a result, in each iteration we will see the string with the user's name itself, not an array:

php'name1'
'name2'
'name3'