MongoDB からのデータの読み取り

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require 'bundler/inline'
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gemfile do
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  source 'https://rubygems.org'
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  gem 'mongo'
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end
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uri = '<connection string>'
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Mongo::Client.new(uri) do |client|
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  database = client.use('<database name>')
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  collection = database['<collection name>']
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 # Start example code here
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  # End example code here
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end

document = collection.find(name: '<value>').first
puts document

results = collection.find(founded_year: '<value>')

result = collection.count_documents
puts "Number of documents: #{result}"

result = collection.count_documents('key': '<value>')
puts "value: #{result}"

result = collection.estimated_document_count
puts "Estimated number of documents: #{result}"

results = collection.distinct('field')

stream = collection.watch
collection.insert_one(a: 1)
doc = stream.first
process(doc)