错误：类型不匹配。值[00,00,00]与timeofday类型不匹配

Question

我想从mysql数据中创建一个json形式的谷歌折线图。 JSON数据采用以下格式：

{
    "result": [
        {
            "Date": "Dec 17,2017",
            "start_time": "22,08,17",
            "selected_time": "[00,00,00]"
        },
        {
            "Date": "Dec 18,2017",
            "start_time": "21,48,57",
            "selected_time": "[00,00,00]"
        },
        {
            "Date": "Dec 21,2017",
            "start_time": "13,23,05",
            "selected_time": "[00,00,00]"
        },
        {
            "Date": "Dec 22,2017",
            "start_time": "00,13,33",
            "selected_time": "[00,00,00]"
        },
        {
            "Date": "Dec 23,2017",
            "start_time": "14,48,34",
            "selected_time": "[00,00,00]"
        },
        {
            "Date": "Dec 27,2017",
            "start_time": "19,21,34",
            "selected_time": "[00,00,00]"
        }
    ]
}

下面是我正在做的代码。但它不接受start_time和selected_time值，因为它给出了不匹配的错误。我有mysql db中所有这些字段的varchar数据类型。

function callbackFuncWithData(json){   

var data = new google.visualization.DataTable(); 

data.addColumn('string', 'Date');
data.addColumn('timeofday', 'start_time');
data.addColumn('timeofday', 'selected_time');

$.each(json, function (key, value) {
$.each(value, function (key, value) {
var temp = [];
temp = value;
                    alert([temp['Date']+" "+temp['start_time']+" "+temp['selected_time']]);
data.addRows([
[ temp['Date'],temp['start_time'],temp['selected_time']]
]);
});
});
var options = {
        tooltip: {
            ishtml: true
        },
        title: 'Trendlines with multiple lines',
        hAxis: {
            title: 'Date',

        },
         vAxis: {
            title: 'Time'

        },
        pointSize: 5,
          series: {
                0: { pointShape: 'circle' },

            }

        };
var chart = new google.visualization.LineChart(document.getElementById('multipleTrendChart'));
   chart.draw(data, options);
    }
        }).fail(function (jq, text, err) {
        console.log(text + ' - ' + err);
            });
        }  
        </script>
    </head>
    <body>
        <div id="multipleTrendChart"></div>
    </body>
    </html>

但它显示此错误“错误：类型不匹配。值22,08,17与列索引1中的类型timeofday不匹配”。有人请建议我是什么问题。谢谢