Javascript 解析node.js中的csv文件

我正在尝试编写node.js服务器。 服务器应将请求变量保存在本地csv文件中，该文件将不断更新：

获取mt/server/？var1=0&var2=foo

应导致：

var1，var2

0，'foo'

然后，另一个请求应更改该文件：

获取mt/server/？var1=1&var3=bar

var1，var2，var3

0，'foo'

1，，“酒吧”

到目前为止，我只能覆盖该文件

var fs = require('fs');
var http = require('http');
var url = require('url');
var csv = require( "fast-csv" );

var FILENAME = "data.csv";

function onRequest(request, response) {
    if (request.method == 'GET' && request.url[1]=='?') {

        console.log("a user made a request at url:  " + request.url);

        response.writeHead(200, {"Context-type":"text/plain"});
        response.write("something to write");

        var queryObject = url.parse(request.url, true).query;
        console.log(queryObject);

        fast_csv_write(FILENAME,queryObject);
        fast_csv_read(FILENAME);

        response.end();
    }
}

function fast_csv_read(filename)
{
    csv.fromPath(filename)
    .on("data", function(data){
        console.log("current data: ");
        console.log(data);
})
.on("end", function(){
    console.log("done reading");
});

}
function fast_csv_write(filename,queries)
{
    var csvStream = csv.format({headers: true}),
    writableStream = fs.createWriteStream(filename);

    writableStream.on("finish", function(){
    console.log("done writing.");
    });

    csvStream.pipe(writableStream);
    csvStream.write(queries);
    csvStream.end();
}

http.createServer(onRequest).listen(3001);
console.log("server running .... ");

我已经通读了fast csv自述：

但这并没有给我足够的信息

---

有人能解释一下我如何完成这项工作，或者提供更好的文档来帮助我吗？

尝试手动创建csv…不要使用现有的库尝试此库，它比fast csv好得多，也更成熟：