php遍历mysqli结果集

$mysqli = new mysqli("localhost", "username", "password", "database");

if ($mysqli->connect_error) {
    die("连接失败: " . $mysqli->connect_error);
}

$sql = "SELECT id, name FROM users";
$result = $mysqli->query($sql);

if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        echo "id: " . $row["id"]. " - Name: " . $row["name"]. "<br>";
    }
} else {
    echo "0 结果";
}
$mysqli->close();

while($row = $result->fetch_array()) {
    echo "id: " . $row["id"]. " - Name: " . $row["name"]. "<br>";
}

if ($mysqli->connect_error) {
    die("连接失败: " . $mysqli->connect_error);
}

if (!$result) {
    die("查询失败: " . $mysqli->error);
}

if ($result->num_rows > 0) {
    // 遍历结果集
} else {
    echo "0 结果";
}