通过php / Ajax传递Json来更新Highchart图表

Question

我需要使用Ajax调用从.php文件中使用Json来更新Highchart图表。我编写了Ajax函数，我可以调用.php文件，但我想念如何在Json文件中编写数据以及如何更新图表。这是图表使用数据的方式（取自示例Highchart）：

var ranges = [
        [1246406400000, 14.3, 27.7],
        [1246492800000, 14.5, 27.8],
        [1246579200000, 15.5, 29.6],
        [1246665600000, 16.7, 30.7],
        [1246752000000, 16.5, 25.0],
        [1246838400000, 17.8, 25.7],
        [1246924800000, 13.5, 24.8],
        [1247011200000, 10.5, 21.4],
        [1247097600000, 9.2, 23.8],
        [1247184000000, 11.6, 21.8],
        [1247270400000, 10.7, 23.7],
        [1247356800000, 11.0, 23.3],
        [1247443200000, 11.6, 23.7],
        [1247529600000, 11.8, 20.7],
        [1247616000000, 12.6, 22.4],
        [1247702400000, 13.6, 19.6],
        [1247788800000, 11.4, 22.6],
        [1247875200000, 13.2, 25.0],
        [1247961600000, 14.2, 21.6],
        [1248048000000, 13.1, 17.1],
        [1248134400000, 12.2, 15.5],
        [1248220800000, 12.0, 20.8],
        [1248307200000, 12.0, 17.1],
        [1248393600000, 12.7, 18.3],
        [1248480000000, 12.4, 19.4],
        [1248566400000, 12.6, 19.9],
        [1248652800000, 11.9, 20.2],
        [1248739200000, 11.0, 19.3],
        [1248825600000, 10.8, 17.8],
        [1248912000000, 11.8, 18.5],
        [1248998400000, 10.8, 16.1]
    ],
    averages = [
        [1246406400000, 21.5],
        [1246492800000, 22.1],
        [1246579200000, 23],
        [1246665600000, 23.8],
        [1246752000000, 21.4],
        [1246838400000, 21.3],
        [1246924800000, 18.3],
        [1247011200000, 15.4],
        [1247097600000, 16.4],
        [1247184000000, 17.7],
        [1247270400000, 17.5],
        [1247356800000, 17.6],
        [1247443200000, 17.7],
        [1247529600000, 16.8],
        [1247616000000, 17.7],
        [1247702400000, 16.3],
        [1247788800000, 17.8],
        [1247875200000, 18.1],
        [1247961600000, 17.2],
        [1248048000000, 14.4],
        [1248134400000, 13.7],
        [1248220800000, 15.7],
        [1248307200000, 14.6],
        [1248393600000, 15.3],
        [1248480000000, 15.3],
        [1248566400000, 15.8],
        [1248652800000, 15.2],
        [1248739200000, 14.8],
        [1248825600000, 14.4],
        [1248912000000, 15],
        [1248998400000, 13.6]
    ];


Highcharts.chart('container', {

    title: {
        text: 'July temperatures'
    },

    xAxis: {
        type: 'datetime'
    },

    yAxis: {
        title: {
            text: null
        }
    },

    tooltip: {
        crosshairs: true,
        shared: true,
        valueSuffix: '°C'
    },

    legend: {
    },

    series: [{
        name: 'Temperature',
        data: averages,
        zIndex: 1,
        marker: {
            fillColor: 'white',
            lineWidth: 2,
            lineColor: Highcharts.getOptions().colors[0]
        }
    }, {
        name: 'Range',
        data: ranges,
        type: 'arearange',
        lineWidth: 0,
        linkedTo: ':previous',
        color: Highcharts.getOptions().colors[0],
        fillOpacity: 0.3,
        zIndex: 0,
        marker: {
            enabled: false
        }
    }]
});

这是代码： 我的Ajax电话：

function myFunction()
{
    var xmlhttp = new XMLHttpRequest();

xmlhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
            myObj = JSON.parse(this.responseText);
            console.log(myObj);
            //var chart = $('#container').highcharts();
            //chart.series[0].setData([myObj],true);
            // need to update both ranges and averages
    }
};
xmlhttp.open("GET", "connection.php", true);
xmlhttp.send();
        }

Connection.php（跳过连接部分）

$getResults= sqlsrv_query($conn, $str);
echo "Reading data from table<BR>";
if ($getResults == FALSE)
    echo (sqlsrv_errors());

while ($row = sqlsrv_fetch_array($getResults, SQLSRV_FETCH_ASSOC)) {

  echo $row['date'] ." " .$row['avg'] ." " . $row['min'] . " " . $row['max'] . "<BR>";
}

sqlsrv_free_stmt($getResults);

如何将while循环中的值插入Json文件？ 如何在Ajax调用中读取Json文件并更新图表？

由于