试图获取非对象的属性“消息”

Question

My code returns the following error:

Notice: Trying to get property 'message' of non-object in C:\\xampp\\htdocs\\mysqlsample.php on line 11

What do I have to change to get it working?

<?php 

try {
    $handler = new PDO('mysql:host=127.0.0.1;dbname=group_projectdb','root','');
} catch (Exception $e) {
    echo $e->getMessage();
    die();
}
$query = $handler->query('SELECT * FROM security');
while ($r = $query->fetch()) {
    echo $r->message,'<br';
}
?>

Answer 1

As error says you're accessing non-object, try:

echo $r['message'];

PDOStatement::fetch() retrieves results in an associative array or a numbered array, or both.

Answer 2

You're using $query->fetch() which returns an array, yet you're using it as an object $r->message . Either use it as an array $r['message'] , or if you prefer to use objects then change to $query->fetchObject()

Answer 3

You can use fetch and get an object, but you haven't done it yet. 2 ways:

//if you need it this time

while ($r = $query->fetch(PDO::FETCH_OBJ)) {

//if you will use this as object in general every time, or most of times

try {
    $handler = new PDO('mysql:host=127.0.0.1;dbname=group_projectdb','root','');
    $handler->setAttribute(PDO::FETCH_OBJ);
} ...
//rest is the same, you use $query->fetch() and get an object

Answer 4

You're trying to get value as a object by using $r->message but you didn't set the fetch mode while fetching the records.
If you prefer to get value in object form then you have to set fetch mode in object
By using $query->fetch(PDO::FETCH_OBJ) or $query->fetchObject()
Read PHP Manual for further info