此foreach语句仅向数组添加最后一行

Question

How can I change this foreach statement so that it will build an array with all the rows in the particular column? It's currently only adding the last row in column 'first_name' to the array.

try {  
    $stmt = $conn->prepare("SELECT * FROM student");  
    $stmt->execute();
} catch(PDOException $e) {
    echo $e->getMessage();
} 
$rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
$first_names = array();
foreach ($rows as $row) { 
  $first_names = $row['first_name'];
}

Answer 1

you can try this

array_push($first_names, $row['first_name']);

or

$first_names[] = $row['first_name'];

The problem in your code is that you are overwriting your own variable again and again.