@@ -1,5 +1,7 @@ = dm-adapter-simpledb +This is the new version of the adapter now based on Right_Aws which has helped a lot with performance. The rest of this FAQ is a bit dated... + Written by Jeremy Boles Contributers Edward Ocampo-Gooding, Dan Mayer README @@ -32,8 +32,7 @@ module DataMapper def read_many(query) sdb_type = simpledb_type(query.model) - conditions = set_conditions(query, sdb_type) - order = set_sort_order(query, conditions) + conditions, order = set_conditions_and_sort_order(query, sdb_type) results = get_results(query, conditions, order) Collection.new(query) do |collection| @@ -79,51 +78,48 @@ module DataMapper @uri[:domain] end - #sets the conditions for the SDB query - def set_conditions(query, sdb_type) + #sets the conditions and order for the SDB query + def set_conditions_and_sort_order(query, sdb_type) conditions = ["simpledb_type = '#{sdb_type}'"] - if query.conditions.size > 0 - conditions += query.conditions.map do |condition| - operator = case condition[0] - when :eql then '=' - when :not then '!=' - when :gt then '>' - when :gte then '>=' - when :lt then '<' - when :lte then '<=' - else raise "Invalid query operator: #{operator.inspect}" - end - "#{condition[1].name.to_s} #{operator} '#{condition[2].to_s}'" - end - end - conditions - end + # look for query.order.first and insure in conditions + # raise if order if greater than 1 - #adds sort information to SDB query - def set_sort_order(query, conditions) - if query.order!=nil && query.order.length > 0 + if query.order && query.order.length > 0 query_object = query.order[0] #anything sorted on must be a condition for SDB - conditions << "#{query_object.property.name.to_s} > ''" - order = "order by #{query_object.property.name.to_s} #{query_object.direction==:desc ? 'desc' : 'asc'}" + conditions << "#{query_object.property.name} IS NOT NULL" + order = "order by #{query_object.property.name} #{query_object.direction}" else order = "" end + + query.conditions.each do |operator, attribute, value| + operator = case operator + when :eql then '=' + when :not then '!=' + when :gt then '>' + when :gte then '>=' + when :lt then '<' + when :lte then '<=' + else raise "Invalid query operator: #{operator.inspect}" + end + conditions << "#{attribute.name} #{operator} '#{value}'" + end + [conditions,order] end #gets all results or proper number of results depending on the :limit def get_results(query, conditions, order) - query_call = "select * from #{domain} " - query_call = query_call + "where #{conditions.compact.join(' and ')}" if conditions.length > 0 - query_call = query_call + " #{order}" + query_call << "where #{conditions.compact.join(' and ')}" if conditions.length > 0 + query_call << " #{order}" if query.limit!=nil query_limit = query.limit - query_call = query_call + " limit #{query.limit}" + query_call << " limit #{query.limit}" else #on large items force the max limit query_limit = 999999999 #TODO hack for query.limit being nil - query_call = query_call + " limit 2500" + query_call << " limit 2500" end results = sdb.select(query_call) lib/simpledb_adapter.rb 1c32b245606a8802ba3d02c7167565e39ba71088 Dan Mayer dan@devver.net http://github.com/danmayer/dm-adapter-simpledb/commit/69a14a733fc9e556fa3c05fd40f1fd8655ac3274 69a14a733fc9e556fa3c05fd40f1fd8655ac3274 2009-06-23T22:42:35-07:00 2009-06-23T22:42:35-07:00 merged in the rectorings from the BRUG meeting b99f33ab78fe8139c749ea3d6de06caa0ae9f3af Dan Mayer dan@devver.net