Selecting table data with PDO statements [duplicate]

Answer 1

Your code is wrong:

$query = $dbh->prepare("SELECT * FROM students");
$query->execute();
$result = $dbh->query($query);

After executing a prepared statement, you can just call fetchAll() on it:

$query = $dbh->prepare("SELECT * FROM students");
$query->execute();
$result = $query->fetchAll();

The rest of your code will work fine once you remove the semicolon after the foreach.