How to update a couchdb document with Ruby - ruby-on-rails

Question

I have a Rails application with MYSQL backend. Upon saving data in MYSQL, it pushes some data to Couchdb using curl commands. However, I am unable to update that very same document. I dont know how query from couchdb and use _rev id to update. Here is how am creating and pushing a couchdb document.
require 'net/http'
require 'uri'
require 'json'
def push_to_couchdb
url = URI.parse("http://127.0.0.1:5984/m5fcash/100")
request = Net::HTTP::Put.new(url)
request.body = JSON.dump({
"fname" => "fname",
"lanme" => "lname",
"type" => "demo",
"facility" => "spectre"
})
req_options = {
use_ssl: url.scheme == "https",
}
response = Net::HTTP.start(url.hostname, url.port, req_options) do |http|
http.request(request)
end
end
This is how am trying to query the document and extract its _rev id
def get_couch_doc
uri = URI.parse("http://127.0.0.1:5984/m5fcash/100")
response = Net::HTTP.get_response(uri)
raise response.inspect
end
I expect raise response.inspect to gove a couchdb document from which I will exctract a _rev id. But all I get is #. How can I query a document in Ruby using curl??

Answer 1

It's not entirely clear to me from your code what you're trying to do, so I'll try to explain in general terms.
In order to read a specific document revsion, you need to use the rev=... query parameter. This is probably not what you want. In your get_couch_doc you can't have a request body. It looks like you're trying to fetch a document based on specific data in the body -- for this you need to create a secondary index, known as a view in CouchDB.
If you want to be able to query based on the lanme (maybe that should be lname?) field, you'd make a view where the map could look something like
function(doc) {
if (doc.lname) {
emit(doc.lname, null);
}
}
If you want to update a document, you need to do a PUT database/doc_id with the rev=.... query parameter on the URL.
CouchDB docs for the document API, and for views.