Экспортирование больших данных в CSV-файл

Question

Я пытаюсь экспортировать большие данные в CSV-файлы. (свыше 20000 строк... можно легко получить более 100000 строк). после попытки загрузки файла происходит сбой - загрузка не удалась из-за сбоев сети. (удалось загрузить файл из 18000 строк, который весит 1,7 МБ, код работал отлично. При превышении 20000 загрузка вылетает)

вот мой код... спасибо!

редактировать - работает в IE, не работает в Chrome

var data2 =     [[data12]];
var csvContent2 = "";
data2.forEach(function (infoArray, index) {

    dataString = Array.prototype.join.call(infoArray, "");
    csvContent2 += index < data2.length ? dataString + '\n' : dataString;

});

var download = function(content, fileName, mimeType) {
var a = document.createElement('a');
    mimeType = mimeType || 'application/octet-stream';

    if (navigator.msSaveBlob) { // IE10
        return navigator.msSaveBlob(new Blob([content], { type: mimeType }), fileName);
    } else if ('download' in a) { //html5 A[download]
        a.href = 'data:' + mimeType + ',' + encodeURIComponent(content);
        a.setAttribute('download', fileName);
        document.body.appendChild(a);
        setTimeout(function() {
        a.click();
        document.body.removeChild(a);
        }, 66);
    return true;
} else { //do iframe dataURL download (old ch+FF):
    var f = document.createElement('iframe');
    document.body.appendChild(f);
    f.src = 'data:' + mimeType + ',' + encodeURIComponent(content);

    setTimeout(function() {
        document.body.removeChild(f);
    }, 333);
    return true;
    }
}

    download(csvContent2, 'GroupB.csv', 'text/csv');

Answer 1

Не берите в голову, только что использовал этот скрипт, с этого веб- http://jsfiddle.net/4zv6r/

           function cloneAndConvert(){

var jsonData = [{firstName:"Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum", lastName:"Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum", age:46}];
for(i=0;i<90000;i++)
{     
   jsonData.push({firstName:"Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum"+i, lastName:"Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum"+i, age:46});
}

var filteredGridData = JSON.parse(JSON.stringify(jsonData))
JSONToCSVConvertor(filteredGridData, "UserReport.csv", true);

}

function JSONToCSVConvertor (JSONData, ReportTitle, ShowLabel) {

//If JSONData is not an object then JSON.parse will parse the JSON string in an Object
var arrData = typeof JSONData != 'object' ? JSON.parse(JSONData) : JSONData;
var CSV = '';    
//This condition will generate the Label/Header
if (ShowLabel) {
    var row = "";

    //This loop will extract the label from 1st index of on array
    for (var index in arrData[0]) {
        //Now convert each value to string and comma-seprated
        row += index + ',';
    }
    row = row.slice(0, -1);
    //append Label row with line break
    CSV += row + '\r\n';
}

//1st loop is to extract each row
for (var i = 0; i < arrData.length; i++) {
    var row = "";
    //2nd loop will extract each column and convert it in string comma-seprated
    for (var index in arrData[i]) {
        row += '"' + arrData[i][index] + '",';
    }
    row.slice(0, row.length - 1);
    //add a line break after each row
    CSV += row + '\r\n';
}

if (CSV == '') {        
    alert("Invalid data");
    return;
}   

//this trick will generate a temp "a" tag
var link = document.createElement("a");    
link.id="lnkDwnldLnk";

//this part will append the anchor tag and remove it after automatic click
document.body.appendChild(link);

var csv = CSV;  
blob = new Blob([csv], { type: 'text/csv' }); 
var csvUrl = window.webkitURL.createObjectURL(blob);
var filename = 'UserExport.csv';
$("#lnkDwnldLnk")
.attr({
    'download': filename,
    'href': csvUrl
}); 

$('#lnkDwnldLnk')[0].click();    
document.body.removeChild(link);

}

Answer 2

Если вы имеете дело с большим количеством данных, то, возможно, вы захотите найти способ сделать память более удобной с помощью StreamSaver.

async function download(){
    const fileStream = streamSaver.createWriteStream('filename.csv')
    const writer = fileStream.getWriter()
    const encoder = new TextEncoder

    for(let row of rows){
        await writer.ready()
        let binary = encoder.encode(data + "\r\n")
        writer.write(uint8array)
    }

    writer.close()
}

Answer 3

Предупреждение, есть некоторые ограничения для URL, например, общая длина URL, включая GET, не должна превышать 2000+ символов в IE, может быть, вы достигнете максимального размера с большим файлом CSV?
Как долго ваш URI? Посмотрите эту ссылку об ограничении IE URI.

Редактировать: Может быть, вы можете попробовать с этим createObjectURL (blob), но это НЕ стабилизированная функция:x