js实现json数据行到列的转换的实例代码

月份郑州-电量新乡-电量安阳-电量
201201 33 29 23
201202 35 26 25
201203 34 27 24
201204 36 28 26
201205 34.3 28.8 24.3
这样，Ext的图表就能把它显示成三个序列了。
我写了如下的函数实现这个功能：
复制代码代码如下:
function CovertData（jsonData,idField, fromField, toField）{
var result = [], curRecord =null, num;
var fromFields = fromField.split（","）;
// 循环整个数组：[{...},{...},{...},...]
for（var idx=0;idx<jsonData.length;idx++）{
num = findIdx（result, idField, jsonData[idx][idField]）;
if（num！=-1）{
curRecord = result[num];
}
else{
curRecord = {};
};
// 循环每个json对象中的字段
for（var key in jsonData[idx]）{
// 处理转换的数据内容
for（var i=0;i<fromFields.length;i++）{
if（key == fromFields[i]）{
curRecord[jsonData[idx][toField]+"-" + fromFields[i]] = jsonData[idx][key];
break;
}
}
// 除数据内容外，只处理标识字段数据
if（key == idField）{
curRecord[key] = jsonData[idx][key];
}
}
if（num==-1）{
result.push（curRecord）;
}
}
return result;
}

function findIdx（jsonData, columnName, value）{
for（var idx = 0;idx<jsonData.length;idx++）{
if（jsonData[idx][columnName]==value）
return idx;
}
return -1;
}
JsTestDriver的测试代码如下：
TestCase（"Test json data row to column",{
setUp:function（）{
this.jsonData = [{yearmonth:201201,ppq:23,spq:27,company:"dfsoft"},
{yearmonth:201202,ppq:33,spq:38,company:"dfsoft"},
{yearmonth:201203,ppq:43,spq:49,company:"dfsoft"},
{yearmonth:201204,ppq:53,spq:51,company:"dfsoft"},
{yearmonth:201201,ppq:29,spq:26,company:"vcom"},
{yearmonth:201202,ppq:34,spq:38,company:"vcom"},
{yearmonth:201203,ppq:48,spq:43,company:"vcom"},
{yearmonth:201204,ppq:52,spq:59,company:"vcom"}];

var fromField = "ppq,spq", toField = "company", idField = "yearmonth";
this.resultData = CovertData（this.jsonData,idField,fromField, toField）;
},
"test store has columns":function（）{
var month1 = this.resultData[findIdx（this.resultData,"yearmonth",201201）];
var month2 = this.resultData[findIdx（this.resultData,"yearmonth",201202）];
var month3 = this.resultData[findIdx（this.resultData,"yearmonth",201203）];
var month4 = this.resultData[findIdx（this.resultData,"yearmonth",201204）];

assertEquals（4,this.resultData.length）;
assertEquals（"23",month1["dfsoft-ppq"]）;
assertEquals（"29",month1["vcom-ppq"]）;
assertEquals（"33",month2["dfsoft-ppq"]）;
assertEquals（"34",month2["vcom-ppq"]）;
assertEquals（"43",month3["dfsoft-ppq"]）;
assertEquals（"48",month3["vcom-ppq"]）;
assertEquals（"53",month4["dfsoft-ppq"]）;
assertEquals（"52",month4["vcom-ppq"]）;

assertEquals（"27",month1["dfsoft-spq"]）;
assertEquals（"26",month1["vcom-spq"]）;
assertEquals（"38",month2["dfsoft-spq"]）;
assertEquals（"38",month2["vcom-spq"]）;
assertEquals（"49",month3["dfsoft-spq"]）;
assertEquals（"43",month3["vcom-spq"]）;
assertEquals（"51",month4["dfsoft-spq"]）;
assertEquals（"59",month4["vcom-spq"]）;
}
}）

测试通过，表示转换成功。