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author | Joshua Peek <josh@joshpeek.com> | 2011-03-30 21:04:33 -0500 |
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committer | Joshua Peek <josh@joshpeek.com> | 2011-03-30 21:04:33 -0500 |
commit | 56a5da89dbcdd6d73f26f5c1be6221b684574b2b (patch) | |
tree | 577fbc16d37ed54bbda1a2a7477894caa6a7bfff /activerecord/lib/active_record/relation/calculations.rb | |
parent | 5df076ad0965dc684afff8a019fd9f92a53ada76 (diff) | |
parent | 58c3ec1b7b7ee073edf9c245de5d06426be60a25 (diff) | |
download | rails-56a5da89dbcdd6d73f26f5c1be6221b684574b2b.tar.gz rails-56a5da89dbcdd6d73f26f5c1be6221b684574b2b.tar.bz2 rails-56a5da89dbcdd6d73f26f5c1be6221b684574b2b.zip |
Merge branch 'master' into sprockets
Conflicts:
railties/lib/rails/application/configuration.rb
Diffstat (limited to 'activerecord/lib/active_record/relation/calculations.rb')
-rw-r--r-- | activerecord/lib/active_record/relation/calculations.rb | 35 |
1 files changed, 23 insertions, 12 deletions
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb index c1842b1a96..869eebfa34 100644 --- a/activerecord/lib/active_record/relation/calculations.rb +++ b/activerecord/lib/active_record/relation/calculations.rb @@ -196,24 +196,22 @@ module ActiveRecord end def execute_simple_calculation(operation, column_name, distinct) #:nodoc: - column = aggregate_column(column_name) - # Postgresql doesn't like ORDER BY when there are no GROUP BY relation = except(:order) - select_value = operation_over_aggregate_column(column, operation, distinct) - relation.select_values = [select_value] + if operation == "count" && (relation.limit_value || relation.offset_value) + # Shortcut when limit is zero. + return 0 if relation.limit_value == 0 - query_builder = relation.arel + query_builder = build_count_subquery(relation, column_name, distinct) + else + column = aggregate_column(column_name) - if operation == "count" - limit = relation.limit_value - offset = relation.offset_value + select_value = operation_over_aggregate_column(column, operation, distinct) - unless limit && offset - query_builder.limit = nil - query_builder.offset = nil - end + relation.select_values = [select_value] + + query_builder = relation.arel end type_cast_calculated_value(@klass.connection.select_value(query_builder.to_sql), column_for(column_name), operation) @@ -312,5 +310,18 @@ module ActiveRecord select if select !~ /(,|\*)/ end end + + def build_count_subquery(relation, column_name, distinct) + column_alias = Arel.sql('count_column') + subquery_alias = Arel.sql('subquery_for_count') + + aliased_column = aggregate_column(column_name == :all ? 1 : column_name).as(column_alias) + relation.select_values = [aliased_column] + subquery = relation.arel.as(subquery_alias) + + sm = Arel::SelectManager.new relation.engine + select_value = operation_over_aggregate_column(column_alias, 'count', distinct) + sm.project(select_value).from(subquery) + end end end |