Mysqli数据库连接问题

Question

I am currently using mysqli to crate a connection to my database. My host server doesnt support PDO connections so that is why I am using mysqli. When making the connection I am getting this error:

Fatal error: Call to undefined method mysqli_result::fetchAll()

Is fetchAll() not part of mysqli?

PHP Connect to DB

$mysqli = new mysqli('localhost', 'user', 'password', 'database');

if (mysqli_connect_error()) {
    die('Connect Error (' . mysqli_connect_errno() . ') '
            . mysqli_connect_error());
}
else {
echo ('Success... '); 
}

    $sql = "SELECT * 
            FROM `categories`
            WHERE `master` = 0";
    $statement = $mysqli->query($sql);
    $list = $statement->fetchAll();

Answer 1

When you call $mysqli->query($sql), this can return a mysqli_result object, or the value false in case of an error. I think that your query is not successful, and returns the value false, and of course if you ask for false->fetchAll() this will give an error message.

So you have to check first, if the query was successful (use the === operator and check for false), and afterwards you can work with the result of the query.

P.S. That's why i never write functions myself, with mixed typed return values...