1. How to obtain the series in echarts that is combined into a histogram based on the data of the json file?
2. The following is json data: {
{
"info": {
"userCount": 906,
"have_num": 693,
"pass_num": 417,
"unpass_num": 276,
"pass_rate": "60.17%",
"make_have": 357,
"make_pass": 336,
"make_unpass": 21,
"make_rate": "94.12%"},
"item": [
{
"PlaceName": "朔州市安全考试中心",
"Detail": [
{
"Name": "低压电工作业",
"Num": 433,
"Pass": 372,
"Fail": 23,
"Miss": 38
},
{
"Name": "高压电工作业",
"Num": 283,
"Pass": 252,
"Fail": 25,
"Miss": 6
},
{
"Name": "熔化焊接与热切割作业",
"Num": 178,
"Pass": 131,
"Fail": 4,
"Miss": 43
}
]
},
{
"PlaceName": "朔州考点2测试",
"Detail": [
{
"Name": "低压电工作业",
"Num": 4,
"Pass": 1,
"Fail": 2,
"Miss": 1
}
]
},
{
"PlaceName": "朔州考点3测试",
"Detail": [
{
"Name": "高压电工作业",
"Num": 4,
"Pass": 0,
"Fail": 0,
"Miss": 4
},
{
"Name": "熔化焊接与热切割作业",
"Num": 4,
"Pass": 0,
"Fail": 0,
"Miss": 4
}
]
}]
}
3. The following is an example of the histogram that needs to be made: 
4. Sample code:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>echarts</title>
<script src="echarts/echarts.js"></script>
<script src="jquery/jquery-1.11.0.min.js"></script>
<!--<script src="echarts/theme/macarons.js"></script>-->
</head>
<body>
<p>
</p>
<p id="main" style="width: 800px;height: 600px;"></p>
<script type="text/javascript">
var myChart=echarts.init(document.getElementById('main'));
var bcBySeriesIndex = ['low voltage', 'low voltage', 'low voltage',
'高压', '高压', '高压', '焊接', '焊接', '焊接'
];
var option= {// title: {
// text: 'Statistical Chart of Examination Situation at Test Centers on April 6, 2017'
// },
toolbox: {
show: true,
feature: {
dataView: {
show: true,
readOnly: false
},
magicType: {
show: true,
type: ['line', 'bar']
},
restore: {
show: true
},
saveAsImage: {
show: true
}
}
},
calculable: true,
tooltip: {
trigger: 'axis',
axisPointer: { // 坐标轴指示器，坐标轴触发有效
type: 'shadow' // 默认为直线，可选为：'line' | 'shadow'
},
formatter: function(params) {
var html = [];
var category = {};
echarts.util.each(params, function(param) {
var catName = param.seriesName;
var bc = bcBySeriesIndex[param.seriesIndex];
if (!category[catName]) {
category[catName] = {};
}
category[catName][bc] = param.value;
});// console.log(category);
echarts.util.each(category, function(cate, key) {
html.push(
'<tr>',
'<td>', key, '</td>',
'<td>', cate.低压, '</td>',
'<td>', cate.高压, '</td>',
'<td>', cate.焊接, '</td>',
'</tr>'
);
});
return '<table border=0><tbody>' +
'<tr><td>统计</td><td>低压</td><td>高压</td><td>焊接</td></tr>' +
html.join('') +
'</tbody></table>';
}
},
legend: {
data: [
'及格', '不及格', '未考'
],
x: 'center'
},
grid: {
left: '3%',
right: '4%',
bottom: '3%',
containLabel: true
},
xAxis: [{
type: 'category',
data: ['考点1', '考点2', '考点3', '考点4', '考点5', '考点6']
}],
yAxis: [{
type: 'value'
}],
series: [
{
name: '及格',
type: 'bar',
stack: '低压',
data: [150, 100, 120, 160, 80, 111]
}, {
name: '不及格',
type: 'bar',
stack: '低压',
data: [20, 10, 30, 11, 13, 2]
}, {
name: '未考',
type: 'bar',
stack: '低压',
data: [10, 20, 30, 12, 14, 18],
label: {
normal: {
show: true,
position: 'top',
formatter: '低压',
textStyle: {
color: '#333'
}
}
}
},
{
name: '及格',
type: 'bar',
stack: '高压',
data: [100, 120, 70, 85, 72, 83]
}, {
name: '不及格',
type: 'bar',
stack: '高压',
data: [14, 12, 2, 5, 6, 8]
}, {
name: '未考',
type: 'bar',
stack: '高压',
data: [3, 1, 2, 0, 4, 15, 10],
label: {
normal: {
show: true,
position: 'top',
formatter: '高压',
textStyle: {
color: '#333'
}
}
}
},
{
name: '及格',
type: 'bar',
stack: '焊接',
data: [99, 90, 70, 111, 79, 87]
}, {
name: '不及格',
type: 'bar',
stack: '焊接',
data: [2, 5, 2, 4, 6, 3]
}, {
name: '未考',
type: 'bar',
stack: '焊接',
data: [2, 3, 5, 0, 1, 3],
label: {
normal: {
show: true,
position: 'top',
formatter: '焊接',
textStyle: {
color: '#333'
}
}
}
}
]
};
myChart.setOption(option);
</script>
</body>
</html>
5. How to replace the data in the example with the data of the json file?
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
Documentation
Isn’t it very clear here