gistfile1.rb

query = "proxyIn_ssim:1n79h430f AND -next_ssim:[* TO *]"
results = ActiveFedora::SolrService.query(query)

ActiveFedora::SolrService.query(query).map { |res| res.slice('proxyIn_ssim', 'proxyFor_ssim', 'id') }
# => [{"proxyIn_ssim"=>["1n79h430f"], "proxyFor_ssim"=>["8w32r5659"], "id"=>"1n79h430f/members/37fe7adb-828e-4114-9c20-b71ae02efb6d"},
#     {"proxyIn_ssim"=>["1n79h430f"], "proxyFor_ssim"=>["8w32r5659"], "id"=>"1n79h430f/members/07b0926e-97a8-456f-bf4d-4a926608de94"}]

query2 = "proxyIn_ssim:1n79h430f"
ActiveFedora::SolrService.count(query2)
#=> 642
ActiveFedora::SolrService.query(query2, rows: 1000).map { |res| res.fetch('proxyFor_ssim').first }.uniq.count
#=> 321