diff options
Diffstat (limited to 'activerecord/lib/active_record/relation/merger.rb')
-rw-r--r-- | activerecord/lib/active_record/relation/merger.rb | 114 |
1 files changed, 78 insertions, 36 deletions
diff --git a/activerecord/lib/active_record/relation/merger.rb b/activerecord/lib/active_record/relation/merger.rb index eb23e92fb8..182b9ed89c 100644 --- a/activerecord/lib/active_record/relation/merger.rb +++ b/activerecord/lib/active_record/relation/merger.rb @@ -22,7 +22,7 @@ module ActiveRecord # build a relation to merge in rather than directly merging # the values. def other - other = Relation.new(relation.klass, relation.table) + other = Relation.create(relation.klass, relation.table) hash.each { |k, v| if k == :joins if Hash === v @@ -39,20 +39,17 @@ module ActiveRecord end class Merger # :nodoc: - attr_reader :relation, :values + attr_reader :relation, :values, :other def initialize(relation, other) - if other.default_scoped? && other.klass != relation.klass - other = other.with_default_scope - end - @relation = relation @values = other.values + @other = other end NORMAL_VALUES = Relation::SINGLE_VALUE_METHODS + Relation::MULTI_VALUE_METHODS - - [:where, :order, :bind, :reverse_order, :lock, :create_with, :reordering, :from] # :nodoc: + [:joins, :where, :order, :bind, :reverse_order, :lock, :create_with, :reordering, :from] # :nodoc: def normal_values NORMAL_VALUES @@ -61,26 +58,78 @@ module ActiveRecord def merge normal_values.each do |name| value = values[name] - relation.send("#{name}!", *value) unless value.blank? + # The unless clause is here mostly for performance reasons (since the `send` call might be moderately + # expensive), most of the time the value is going to be `nil` or `.blank?`, the only catch is that + # `false.blank?` returns `true`, so there needs to be an extra check so that explicit `false` values + # don't fall through the cracks. + relation.send("#{name}!", *value) unless value.nil? || (value.blank? && false != value) end merge_multi_values merge_single_values + merge_joins relation end private + def merge_joins + return if values[:joins].blank? + + if other.klass == relation.klass + relation.joins!(*values[:joins]) + else + joins_dependency, rest = values[:joins].partition do |join| + case join + when Hash, Symbol, Array + true + else + false + end + end + + join_dependency = ActiveRecord::Associations::JoinDependency.new(other.klass, + joins_dependency, + []) + relation.joins! rest + + @relation = relation.joins join_dependency + end + end + def merge_multi_values - relation.where_values = merged_wheres - relation.bind_values = merged_binds + lhs_wheres = relation.where_values + rhs_wheres = values[:where] || [] + + lhs_binds = relation.bind_values + rhs_binds = values[:bind] || [] + + removed, kept = partition_overwrites(lhs_wheres, rhs_wheres) + + where_values = kept + rhs_wheres + bind_values = filter_binds(lhs_binds, removed) + rhs_binds + + conn = relation.klass.connection + bv_index = 0 + where_values.map! do |node| + if Arel::Nodes::Equality === node && Arel::Nodes::BindParam === node.right + substitute = conn.substitute_at(bind_values[bv_index].first, bv_index) + bv_index += 1 + Arel::Nodes::Equality.new(node.left, substitute) + else + node + end + end + + relation.where_values = where_values + relation.bind_values = bind_values if values[:reordering] # override any order specified in the original relation relation.reorder! values[:order] elsif values[:order] - # merge in order_values from r + # merge in order_values from relation relation.order! values[:order] end @@ -97,35 +146,28 @@ module ActiveRecord end end - def merged_binds - if values[:bind] - (relation.bind_values + values[:bind]).uniq(&:first) - else - relation.bind_values - end - end + def filter_binds(lhs_binds, removed_wheres) + return lhs_binds if removed_wheres.empty? - def merged_wheres - values[:where] ||= [] + set = Set.new removed_wheres.map { |x| x.left.name } + lhs_binds.dup.delete_if { |col,_| set.include? col.name } + end - if values[:where].empty? || relation.where_values.empty? - relation.where_values + values[:where] - else - # Remove equalities from the existing relation with a LHS which is - # present in the relation being merged in. + # Remove equalities from the existing relation with a LHS which is + # present in the relation being merged in. + # returns [things_to_remove, things_to_keep] + def partition_overwrites(lhs_wheres, rhs_wheres) + if lhs_wheres.empty? || rhs_wheres.empty? + return [[], lhs_wheres] + end - seen = Set.new - values[:where].each { |w| - if w.respond_to?(:operator) && w.operator == :== - seen << w.left - end - } + nodes = rhs_wheres.find_all do |w| + w.respond_to?(:operator) && w.operator == :== + end + seen = Set.new(nodes) { |node| node.left } - relation.where_values.reject { |w| - w.respond_to?(:operator) && - w.operator == :== && - seen.include?(w.left) - } + values[:where] + lhs_wheres.partition do |w| + w.respond_to?(:operator) && w.operator == :== && seen.include?(w.left) end end end |