Download data from UnData of ONU

Question

I want to know the population of some countries over the period 1960-2015.

I found this site that contains this data and I'm interested in downloading it using Node.js.

I read that there are some APIs but I didn't understand how to use them.

I went to this site (which allows you to create and download the query in XML format) and I looked for the table that interests me. I set the parameters that interest me and I downloaded the query:

<?xml version="1.0" encoding="utf-8"?>
<StructureSpecificDataQuery xmlns="http://www.sdmx.org/resources/sdmxml/schemas/v2_1/message">
  <!--NSI Web client v3.11.0.0-->
  <Header>
    <ID>IDREF47</ID>
    <Test>false</Test>
    <Prepared>2018-04-07T10:31:11.2310882+02:00</Prepared>
    <Sender id="Unknown" />
    <Receiver id="Unknown" />
  </Header>
  <Query>
    <ReturnDetails defaultLimit="361914" detail="Full" observationAction="Active" xmlns="http://www.sdmx.org/resources/sdmxml/schemas/v2_1/query">
      <Structure dimensionAtObservation="TIME_PERIOD" structureID="StructureId">
        <Structure xmlns="http://www.sdmx.org/resources/sdmxml/schemas/v2_1/common">
          <Ref agencyID="WB" id="WDI" version="1.0" xmlns="" />
        </Structure>
      </Structure>
    </ReturnDetails>
    <DataWhere xmlns="http://www.sdmx.org/resources/sdmxml/schemas/v2_1/query">
      <Dataflow>
        <Ref agencyID="WB" id="DF_UNDATA_WDI" version="1.0" xmlns="" />
      </Dataflow>
      <TimeDimensionValue>
        <TimeValue operator="greaterThanOrEqual">1960-01-01</TimeValue>
        <TimeValue operator="lessThanOrEqual">2015-12-31</TimeValue>
      </TimeDimensionValue>
      <Or>
        <DimensionValue>
          <ID>SERIES</ID>
          <Value operator="equal">SP_POP_TOTL</Value>
        </DimensionValue>
      </Or>
      <Or>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">ALB</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">AUT</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">BEL</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">BGR</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">HRV</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">CYP</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">DNK</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">EST</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">FIN</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">FRA</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">DEU</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">GRC</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">ISL</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">ITA</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">LVA</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">NLD</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">NOR</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">POL</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">PRT</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">ROM</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">SVK</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">SVN</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">ESP</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">SWE</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">CHE</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">GBR</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">EMU</Value>
        </DimensionValue>
        <DimensionValue>
          <ID>REF_AREA</ID>
          <Value operator="equal">EUU</Value>
        </DimensionValue>
      </Or>
    </DataWhere>
  </Query>
</StructureSpecificDataQuery>

Now I have to do an HTTP Post request. I install request-promise package.

Now I don't know what to do. I thought about using this code, but where do I insert the downloaded query?

var cheerio = require('cheerio');
var request = require('request-promise');
var methods = {};

var options = {
    uri: '???',
    transform: function(body) {
        return cheerio.load(body);
    }
};

methods.download = async function(req, res) {
    request(options)
    .then(function($) {
        // Process html like you would with jQuery...
    })
    .catch(function(err) {
        // Crawling failed or Cheerio choked...
    });
}

Can someone help me?

Answer 1

The SDMX API provided is old and not easy to use. Personally I would just choose the required data from the table and download it in csv or xml format. That's far easier than using the outdated API.