使用单例设计模式获取数据库数据

Question

I'm using singleton design pattern for connect to database.In below I run a query on my database and I want to fetch data from this query :

$db = Db::connect();
$query = $db->query("SELECT * FROM myTable");
while ($row = ???) {
// echo 'myTable' fields here. like = echo $row['someField']
}

my Db class:

class Db
{
    private $connection;
    private static $instance;

    private function __construct()
    {
        $host = "localhost";
        $user = "root";
        $pass = "";
        $name = "dictionary";

        $this->connection = new mysqli($host, $user, $pass, $name);
    }

    public static function connect()
    {
        if (self::$instance == null) {
            self::$instance = new Db();
        }

        return self::$instance;
    }

    public function query($sql)
    {
        $result = $this->connection->query($sql);
        $records = array();
        while ($row = $result->fetch_assoc()) {
            $records[] = $row;
        }
        return $records;
    }
}

What should I write instead of ??? in my code ?

Answer 1

Replace

while ($row = ???) {
    // echo 'myTable' fields here. like = echo $row['someField']
}

with

foreach($query as $row)
    echo $row['someField'];

Note : You may want to rename $query to $rows, for example, since this is a more appropriate name.