我的AJAX没有正确输出图表

Question

有没有人知道为什么我的AJAX函数会单独返回每个字符。例如。

testNew.html:150 i
testNew.html:150 t
testNew.html:150 e
testNew.html:150 m

应该在图表上返回完整的单词。但它在控制台上打印单个字母并在图表上打印undefined。

javascript中的AJAX代码

$(document).ready(function(){

$.ajax({
    url: "BaseClass.php",
    data: { action : 'getResults' },
    datatype: "application/json",
    method: "GET",
    success: function(data) {
        console.log(data); // Produces the whole array of data from the php query fine.
        var item = [];
        var freq = [];



        for(var i in data) {
            console.log(data[i]); //produces each letter individually
            item.push("Item " + data[i].item_description);
            freq.push(data[i].item_id);
        }

        console.log(data[0].item_description); //Outputs undefined

        var chartdata = {
            labels: item,
            datasets : [
                {
                    label: '...',
                    backgroundColor: 'rgba(200, 200, 200, 0.75)',
                    borderColor: 'rgba(200, 200, 200, 0.75)',
                    hoverBackgroundColor: 'rgba(200, 200, 200, 1)',
                    hoverBorderColor: 'rgba(200, 200, 200, 1)',
                    data: freq
                }
            ]
        };

        var ctx = $("#mycanvas");

        var barGraph = new Chart(ctx, {
            type: 'bar',
            data: chartdata
        });
    },
    error: function(data) {
        console.log(data);
    }
});

}）;

MySQLDao.php - 保存所有查询，获取查询结果并发送到javascript：

<?php

    error_reporting(E_ALL); ini_set('display_errors', 1);

    //Class for holding queries
    class MySQLDao
    {

        var $dbhost = null;
        var $dbuser = null;
        var $dbpass = null;
        var $mysqli = null;
        var $dbname = null;
        var $result = null;


        //constructor
        function __construct()
        {
            $this->dbhost = Conn::$dbhost;
            $this->dbuser = Conn::$dbuser;
            $this->dbpass = Conn::$dbpass;
            $this->dbname = Conn::$dbname;
        }

        //Attempt a connection to the database
        public function openConnection()
        {   

            //Try and connect to the database
            $this->mysqli = new mysqli($this->dbhost, $this->dbuser, $this->dbpass, $this->dbname);
            //If the connection threw an error, report it
            if (mysqli_connect_errno())
            {
                return false;
            }
            else
            {
                return true;
            }
        }

        //Get method for retrieving the database conection
        public function getConnection()
        {
            return $this->mysqli;
        }

        //Close the connection to the database
        public function closeConnection()
        {
            //If there is a connection to the database then close it
            if ($this->mysqli != null)
                $this->mysqli->close();
        }

        //-----------------------------------QUERY METHODS-------------------------------------

        public function getResults()
        {


            $sql = "SELECT * FROM item";

            $result = $this->mysqli->query($sql);


            //loop through the returned data
            $data = array();
            foreach ($result as $row) {
                $data[] = $row;
            }


            return $data;

        }

    }
?>

BaseClass.php：

<?php

    error_reporting(E_ALL); ini_set('display_errors', 1);

    require("Conn.php");
    require("MySQLDao.php");

    //$param=$_REQUEST['action'];

    //echo json_encode($_GET);


    //echo var_dump(json_encode($_GET));


    $handle = fopen("php://input", "rb");
    $param = $_REQUEST['action'];
    while (!feof($handle)) {
        $param .= fread($handle, 8192);
    }
    fclose($handle);


    if (empty($param))
    {
        $returnValue["status"] = false;
        $returnValue["title"] = "Error";
        $returnValue["message"] = "No Data Recieved paige" .$param ."...";
        echo json_encode($returnValue);
        return;
    }
    else
    {
        $dao = new MySQLDao();
        if ($dao->openConnection() == false)
        {
            $returnValue["status"] = false;
            $returnValue["title"] = "Error";
            $returnValue["message"] = "Connection Could Not Be Established Between Server And Database";
            ob_clean();
            echo json_encode($returnValue);
        }
        else
        {
            //Decodes data, dont change
            $body = json_decode($param, true);
            $recieved = $body["data"];

            //Gets the result of a query
            $result = $dao->getResults($recieved);


        }
        $dao->closeConnection();

        //Return the result of the query
        ob_clean();


        //echo json_encode("param" .$param);
        //echo json_encode("body" .$body);
        //echo json_encode("recieved" .$recieved);
        //echo json_encode("result" .$result);



        echo "Your message : ", json_encode($result); 

        exit();


    }
?>