如何使用流星将存储在数据库中的json转换为csv [英] How to convert json stored in DB into csv using meteor

问题描述

我想下载从数据库（nodeDB）生成的CSV文件，该文件具有以下条目。

这些条目应仅用作标题。

I want to download a CSV file generated from a database (nodeDB) which has the following entries.
These entries should act as headers only.

{    

    "META": {

        "TEMPLATE_NAME": "B", 

        "TEMPLATE_GROUP": "Product", 
        "KEYWORDS": [
            "cc"
        ], 

        "TEMPLATE_SUBGROUP": ""
    }, 
    "VARIENTS": [
        {
            "NAME": "Brand", 
            "DATATYPE": "Text",
        }

    ]
}

我写了以下代码：

HTML：

<template name="templateForCSV">
    <a href="{{pathFor 'csv'}}" target="_blank">Download the CSV</a>
</template>

JS：

if (Meteor.isServer) {
  Meteor.startup(function () {
    //CSV Download
    var DataCursor=nodeDB.find({});
    if (DataCursor.count() === 0) {
      for(var i=1; i<=DataCursor.length; i++) {
        //Example for Now, has to be changed
        nodeDB.insert({Brand: "Brand" + i,Price: "Price" + i, Description:"Description" + i});
      }
    }
  });
 }

Router.route('/csv', {
  where: 'server',
  action: function () {
    var filename = 'data.csv';
    var fileData = "";

    var headers = {
      'Content-type': 'text/csv',
      'Content-Disposition': "attachment; filename=" + filename
    };
    var records = nodeDB.find();
    // This is the main problem. build a CSV string. Oversimplified. You'd have to escape quotes and commas.
    records.forEach(function(rec) {
      fileData += rec.META + "," + rec.VARIENTS + "," +  "\r\n";
    });
    this.response.writeHead(200, headers);
    return this.response.end(fileData);
  }
});

CSV文件已下载，但为空白。

The CSV file is downloaded but it is blank. What's happening?

推荐答案

首先，假设您的 nodeDB 可以正常工作。您的问题可能是未为 / csv 定义路线，因此只需尝试以下测试即可。

First, assume that your nodeDB works fine. Your problem could be that the route is not defined for /csv, so just try the below to test.

<template name="templateForCSV">
    <a href="/csv" target="_blank">Download the CSV</a>
</template>

如果仍然空白，我想您的 nodeDB 为空白，因此请尝试以下内容进行测试。

If that still turns up blank, I would guess that your nodeDB is blank, so try the below to test.

Router.route('/csv', function () {
    var filename = 'data.csv';
    var fileData = "hello, world";

    var headers = {
      'Content-type': 'text/csv',
      'Content-Disposition': "attachment; filename=" + filename
    };

    this.response.writeHead(200, headers);
    this.response.end(fileData);
  }, {where: "server"});

应下载带有 hello，world的CSV文件。请注意，我将上面的语法更改为所使用的语法。

The CSV file with "hello, world" should be downloaded. Note that I changed the syntax a bit on the above to what I use.

尝试一下，让我们知道它是否有效。

Try this and let us know if it works.

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