gistfile1.rb

ORIG_ARTIST = "Jichael Mackson"
Media.where(:artist => ORIG_ARTIST).each(&:destroy)

ActiveRecord::Base.logger = Logger.new(STDOUT)
require 'factory_girl'
begin
FactoryGirl.define do
  factory :media do
    comment "dummy_foo"
    artist ORIG_ARTIST
    title "Yet another title"
    album_string "Never good enough"
    year "1987"
    length_in_seconds "324.4"
  end
end
rescue FactoryGirl::DuplicateDefinitionError
end

#create the media
media = FactoryGirl.create(:media)

#now searching
artist = "mackson"
title = "title"


## taken from rake task code: 

parser = OptimisticMediaParser.new(artist, title, :include_raw => true)
artists, titles = parser.parse
artists_condition = "";
titles_conditions = ""
match = Array.new



select_stmt = ["artist, title"]

select_stmt_lev_titles = Array.new(titles.count) {|i|
  "levenshtein(substr(title,0,255), :title_#{i})"
}
select_stmt_lev_artists = Array.new(artists.count) {|i|
  "levenshtein(substr(artist,0,255), :artist_#{i})"
}

condition_stmt_soundex_titles = Array.new(titles.count) {|i|
  "dmetaphone_alt(substr(title,0,255)) = dmetaphone_alt(:title_#{i})"
}
condition_stmt_soundex_artists = Array.new(artists.count) {|i|
  "dmetaphone_alt(substr(artist,0,255)) = dmetaphone_alt(:artist_#{i})"
}

values = begin
  title_values = Hash.new
  titles.each_with_index {|t, i|
    title_values[:"title_#{i}"] = t[0..255]
  }
  artist_values = Hash.new
  artists.each_with_index {|a, i|
    title_values[:"artist_#{i}"] = a[0..255]
  }
  title_values.merge(artist_values)
end

select = ActiveRecord::Base.send(:sanitize_sql_array, 
  [(select_stmt + select_stmt_lev_titles + select_stmt_lev_artists).reject{|s| s.blank?}.join(','), values]
)

filter_bad_match = (select_stmt_lev_titles + select_stmt_lev_artists).map {|s|
  "#{s} < 1"
}.join(' OR ')

condition = ActiveRecord::Base.send(:sanitize_sql_array, 
  [
    '(' + 
    ([condition_stmt_soundex_titles.join(' OR '), condition_stmt_soundex_artists.join(' OR '), filter_bad_match].reject{|s| s.blank?}.join(') AND (')) + 
    ')', 
    values
  ]
)

order_by = ActiveRecord::Base.send(:sanitize_sql_array, 
  [(select_stmt_lev_titles + select_stmt_lev_artists).join(' + '), values]
)

Media.select(select).where(condition).order(order_by).first ## ==> nil BUT WHY?