how to arrange data in cloudant NOSQL data base according to time stamp

Question

i have connected nodered to Watson iot platform using raspberry pi, now Watson extends to Cloudant NOSQL databse, the datas are arranged in random manner.When i send getrequest from external app the datas are random, how do i fetch data in order according to timestamp?

ptitzler ptitzler · Accepted Answer · 2017-02-15T18:23:56

Assuming your documents contain a field with a timestamp value you could create a view and query it (https://console.ng.bluemix.net/docs/services/Cloudant/api/creating_views.html#views-mapreduce-).

CouchDB/Cloudant returns view results sorted by the key that's defined in the view definition. Simple example, assuming all docs include a field named date_sent representing a timestamp value:

{
    ...
    "date_sent": "2017-02-09T21:37:20.731Z",
    ...
}

Create a view (replace the placeholders $... as appropriate)

PUT https://$USERNAME:$PASSWORD@$USERNAME.cloudant.com/$DATABASE/_design/$DD_NAME HTTP/1.1

{
 "views" : {
   "docs_sorted_by_date" : {
    "map" : "function(doc) { emit(doc.date_sent,1);  }"
   }
 }
}

Query the view

GET https://$USERNAME:$PASSWORD@$USERNAME.cloudant.com/$DATABASE/_design/$DD_NAME/_view/docs_sorted_by_date HTTP/1.1

how to arrange data in cloudant NOSQL data base according to time stamp

1 Answers