Pie CHart一直说我的第一个专栏是'；t字符串(编辑）

让我给出一个简短的背景：过程如下：DB方法向侧脚本返回一个值->生成JSON->发送到google图表js文件。这将生成一个饼图，但它一直说第一列应该是字符串。。。就是这样！。代码：

PHP类方法：

function select_heuristic_piechart1(&$conn){
        $query = ("SELECT hl_name AS name, count(hl_element2) As counted FROM `heuristic_listings` group by hl_element1");
        $statement = $conn->prepare($query);
        $statement->execute();
        $exist = $statement->fetchAll(PDO::FETCH_ASSOC);
        $rows = array();
        $table = array();
        $table['cols'] = array(
        // Labels for your chart, these represent the column titles.
            array('label' => 'first_header', 'type' => 'string'),
            array('label' => 'second_header', 'type' => 'number')
        );
        foreach($exist as $r) {
          $temp = array();
          // the following line will be used to slice the Pie chart
          $temp[] = array('v' => (string) $r['name']); 
          // Values of each slice
         $temp[] = array('v' => (int) $r['counted']); 
         $rows[] = array('c' => $temp);
        }
        $table['rows'] = $rows;

        return $json = Json_encode($table,true);

接收机和发射机

include './database.php';

$connection = new database();
$conn = $connection->connect_db();
$fetchedResult = $connection->select_heuristic_piechart1($conn);
header('Content-Type: application/json');
$json = json_encode($fetchedResult,true);
echo $json;

以及Ajax：

$.ajax({
  url: "./db/receiver_and_transmitter.php",
  data: 'GET',
  dataType: 'json',
  success: function(data){
        console.log('Yas');
        console.log(data);
        var data = new google.visualization.DataTable(data);
    },
  error:function(data){
      console.log('fail');
      console.log(data);
  } 
});

我不知道什么没有错，该改变什么。有人能给我指正确的方向吗？

$.ajax:收到的JSON

{"cols":[{"label":"first_header","type":"string"}, 
{"label":"second_header","type":"number"}],"rows":[{"c":[{"v":"cwood1r"},
{"v":5}]},{"c":[{"v":"sward2h"},{"v":2}]},{"c":[{"v":"etorres19"},{"v":2}]},
{"c":[{"v":"mfranklinr"},{"v":3}]},{"c":[{"v":"mspencerd"},{"v":21}]},{"c":
[{"v":"jknight1y"},{"v":5}]},{"c":[{"v":"hhoward3"},{"v":4}]},{"c":
[{"v":"pross6"},{"v":8}]},{"c":[{"v":"swagner7"},{"v":23}]},{"c":
[{"v":"ajohnston1a"},{"v":8}]},{"c":[{"v":"dalexander1q"},{"v":2}]},{"c":
[{"v":"rmendoza1u"},{"v":2}]},{"c":[{"v":"mmurphy1f"},{"v":5}]},{"c":
[{"v":"rthomasp"},{"v":8}]},{"c":[{"v":"wsullivan5q"},{"v":1}]},{"c":
[{"v":"bperkins3f"},{"v":3}]},{"c":[{"v":"csimpson1j"},{"v":4}]},{"c":
[{"v":"mortiz2e"},{"v":10}]},{"c":[{"v":"sriley1h"},{"v":2}]},{"c":
[{"v":"tbryantf"},{"v":10}]},{"c":[{"v":"esimmons15"},{"v":5}]},{"c":
[{"v":"psullivan35"},{"v":2}]},{"c":[{"v":"jwatson9"},{"v":7}]},{"c":
[{"v":"jcampbell1v"},{"v":2}]},{"c":[{"v":"rford14"},{"v":5}]},{"c":
[{"v":"jnichols4m"},{"v":1}]},{"c":[{"v":"agreenm"},{"v":1}]},{"c":
[{"v":"rmorris1"},{"v":4}]},{"c":[{"v":"pboyd16"},{"v":1}]},{"c":
[{"v":"jdixon2"},{"v":12}]},{"c":[{"v":"kbrownv"},{"v":8}]},{"c":
[{"v":"slarson2l"},{"v":2}]},{"c":[{"v":"lrileyn"},{"v":9}]},{"c":
[{"v":"mholmes1t"},{"v":5}]},{"c":[{"v":"phill4"},{"v":5}]},{"c":
[{"v":"pwalkerh"},{"v":2}]},{"c":[{"v":"thawkins1g"},{"v":6}]},{"c":
[{"v":"crussell0"},{"v":27}]},{"c":[{"v":"cweaver3s"},{"v":2}]},{"c":
[{"v":"fgonzalesb"},{"v":8}]},{"c":[{"v":"elopez10"},{"v":3}]},{"c":
[{"v":"pnichols4f"},{"v":1}]},{"c":[{"v":"swallace1i"},{"v":4}]}]}