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Preload uses exclusive scope [#643 state:resolved]

With self referential associations, the scope for the the top level should not affect fetching of associations, for example
when doing

Person.male.find :all, :include => :friends

we should load all of the friends for each male, not just the male friends.
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1 parent eb457ce commit 5cebe69e74d411c3c9e5f6ab9d4b2b16ee36177c @fcheung fcheung committed Dec 19, 2008
@@ -43,7 +43,7 @@ def self.included(base)
# loading in a more high-level (application developer-friendly) manner.
module ClassMethods
protected
-
+
# Eager loads the named associations for the given ActiveRecord record(s).
#
# In this description, 'association name' shall refer to the name passed
@@ -113,7 +113,7 @@ def preload_one_association(records, association, preload_options={})
# unnecessarily
records.group_by {|record| class_to_reflection[record.class] ||= record.class.reflections[association]}.each do |reflection, records|
raise ConfigurationError, "Association named '#{ association }' was not found; perhaps you misspelled it?" unless reflection
-
+
# 'reflection.macro' can return 'belongs_to', 'has_many', etc. Thus,
# the following could call 'preload_belongs_to_association',
# 'preload_has_many_association', etc.
@@ -128,7 +128,7 @@ def add_preloaded_records_to_collection(parent_records, reflection_name, associa
association_proxy.target.push(*[associated_record].flatten)
end
end
-
+
def add_preloaded_record_to_collection(parent_records, reflection_name, associated_record)
parent_records.each do |parent_record|
parent_record.send("set_#{reflection_name}_target", associated_record)
@@ -183,18 +183,19 @@ def preload_has_and_belongs_to_many_association(records, reflection, preload_opt
conditions = "t0.#{reflection.primary_key_name} #{in_or_equals_for_ids(ids)}"
conditions << append_conditions(reflection, preload_options)
- associated_records = reflection.klass.find(:all, :conditions => [conditions, ids],
- :include => options[:include],
- :joins => "INNER JOIN #{connection.quote_table_name options[:join_table]} t0 ON #{reflection.klass.quoted_table_name}.#{reflection.klass.primary_key} = t0.#{reflection.association_foreign_key}",
- :select => "#{options[:select] || table_name+'.*'}, t0.#{reflection.primary_key_name} as the_parent_record_id",
- :order => options[:order])
-
+ associated_records = reflection.klass.with_exclusive_scope do
+ reflection.klass.find(:all, :conditions => [conditions, ids],
+ :include => options[:include],
+ :joins => "INNER JOIN #{connection.quote_table_name options[:join_table]} t0 ON #{reflection.klass.quoted_table_name}.#{reflection.klass.primary_key} = t0.#{reflection.association_foreign_key}",
+ :select => "#{options[:select] || table_name+'.*'}, t0.#{reflection.primary_key_name} as the_parent_record_id",
+ :order => options[:order])
+ end
set_association_collection_records(id_to_record_map, reflection.name, associated_records, 'the_parent_record_id')
end
def preload_has_one_association(records, reflection, preload_options={})
return if records.first.send("loaded_#{reflection.name}?")
- id_to_record_map, ids = construct_id_map(records)
+ id_to_record_map, ids = construct_id_map(records)
options = reflection.options
records.each {|record| record.send("set_#{reflection.name}_target", nil)}
if options[:through]
@@ -248,7 +249,7 @@ def preload_has_many_association(records, reflection, preload_options={})
reflection.primary_key_name)
end
end
-
+
def preload_through_records(records, reflection, through_association)
through_reflection = reflections[through_association]
through_primary_key = through_reflection.primary_key_name
@@ -333,11 +334,13 @@ def preload_belongs_to_association(records, reflection, preload_options={})
end
conditions = "#{table_name}.#{connection.quote_column_name(primary_key)} #{in_or_equals_for_ids(ids)}"
conditions << append_conditions(reflection, preload_options)
- associated_records = klass.find(:all, :conditions => [conditions, ids],
+ associated_records = klass.with_exclusive_scope do
+ klass.find(:all, :conditions => [conditions, ids],
:include => options[:include],
:select => options[:select],
:joins => options[:joins],
:order => options[:order])
+ end
set_association_single_records(id_map, reflection.name, associated_records, primary_key)
end
end
@@ -355,13 +358,15 @@ def find_associated_records(ids, reflection, preload_options)
conditions << append_conditions(reflection, preload_options)
- reflection.klass.find(:all,
+ reflection.klass.with_exclusive_scope do
+ reflection.klass.find(:all,
:select => (preload_options[:select] || options[:select] || "#{table_name}.*"),
:include => preload_options[:include] || options[:include],
:conditions => [conditions, ids],
:joins => options[:joins],
:group => preload_options[:group] || options[:group],
:order => preload_options[:order] || options[:order])
+ end
end
@@ -771,4 +771,19 @@ def test_eager_loading_with_conditions_on_join_model_preloads
assert_equal author_addresses(:david_address), authors[0].author_address
end
+ def test_preload_belongs_to_uses_exclusive_scope
+ people = Person.males.find(:all, :include => :primary_contact)
+ assert_not_equal people.length, 0
+ people.each do |person|
+ assert_no_queries {assert_not_nil person.primary_contact}
+ assert_equal Person.find(person.id).primary_contact, person.primary_contact
+ end
+ end
+
+ def test_preload_has_many_uses_exclusive_scope
+ people = Person.males.find :all, :include => :agents
+ people.each do |person|
+ assert_equal Person.find(person.id).agents, person.agents
+ end
+ end
end
@@ -1,6 +1,15 @@
michael:
id: 1
first_name: Michael
+ primary_contact_id: 2
+ gender: M
david:
id: 2
- first_name: David
+ first_name: David
+ primary_contact_id: 3
+ gender: M
+susan:
+ id: 3
+ first_name: Susan
+ primary_contact_id: 2
+ gender: F
@@ -7,4 +7,10 @@ class Person < ActiveRecord::Base
has_many :jobs, :through => :references
has_one :favourite_reference, :class_name => 'Reference', :conditions => ['favourite=?', true]
has_many :posts_with_comments_sorted_by_comment_id, :through => :readers, :source => :post, :include => :comments, :order => 'comments.id'
+
+ belongs_to :primary_contact, :class_name => 'Person'
+ has_many :agents, :class_name => 'Person', :foreign_key => 'primary_contact_id'
+
+ named_scope :males, :conditions => { :gender => 'M' }
+ named_scope :females, :conditions => { :gender => 'F' }
end
@@ -298,8 +298,10 @@ def create_table(*args, &block)
end
create_table :people, :force => true do |t|
- t.string :first_name, :null => false
- t.integer :lock_version, :null => false, :default => 0
+ t.string :first_name, :null => false
+ t.references :primary_contact
+ t.string :gender, :limit => 1
+ t.integer :lock_version, :null => false, :default => 0
end
create_table :pets, :primary_key => :pet_id ,:force => true do |t|

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