尝试将数据库数据转换为json但在php中获取未定义的索引错误

Question

我正在使用此代码将数据库数据转换为json，但我在此行中获得了未定义的索引错误$ total [$ name] + = $ score。 提前谢谢。

 <?php
 require_once('conn.php');

 $sql = "select name,score from highscores ";

 $res = mysqli_query($con,$sql); 


if (mysqli_num_rows($res) > 0) {
$result = array();
while($item = mysqli_fetch_assoc($res)){

    $result[]=$item;
}

$total=array();
foreach ($result as $row) {
  $name = $row['name'];
  $score = $row['score'];
  $total[$name] += $score;


$newArray = array();
foreach ($total as $name => $score) {

  array_push($newArray,array('name' => $name, 'score' =>$score));
} 
}
echo json_encode(array("result"=>$newArray));
}