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Accept belongs_to assoc. keys in ActiveRecord queries

Allows you to specify the model association key in a belongs_to
relationship instead of the foreign key.

The following queries are now equivalent:

Post.where(:author_id => Author.first)
Post.where(:author => Author.first)

PriceEstimate.where(:estimate_of_type => 'Treasure', :estimate_of_id => treasure)
PriceEstimate.where(:estimate_of => treasure)
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commit 3da275c4396d7fad250d2b786027ba4f14344bd4 1 parent f2a44ad
@beerlington beerlington authored
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12 activerecord/CHANGELOG.md
@@ -1,5 +1,17 @@
## Rails 4.0.0 (unreleased) ##
+* Accept belongs_to (including polymorphic) association keys in queries
+
+ The following queries are now equivalent:
+
+ Post.where(:author => author)
+ Post.where(:author_id => author)
+
+ PriceEstimate.where(:estimate_of => treasure)
+ PriceEstimate.where(:estimate_of_type => 'Treasure', :estimate_of_id => treasure)
+
+ *Peter Brown*
+
* Use native `mysqldump` command instead of `structure_dump` method
when dumping the database structure to a sql file. Fixes #5547.
View
52 activerecord/lib/active_record/relation/predicate_builder.rb
@@ -1,12 +1,25 @@
module ActiveRecord
class PredicateBuilder # :nodoc:
def self.build_from_hash(engine, attributes, default_table)
- attributes.map do |column, value|
+ queries = []
+
+ attributes.each do |column, value|
table = default_table
if value.is_a?(Hash)
table = Arel::Table.new(column, engine)
- value.map { |k,v| build(table[k.to_sym], v) }
+
+ value.each do |k,v|
+ if rk = find_reflection_key(column, v, v)
+ if rk[:foreign_type]
+ queries << build(table[rk[:foreign_type]], v.class.base_class)
+ end
+
+ k = rk[:foreign_key]
+ end
+
+ queries << build(table[k.to_sym], v)
+ end
else
column = column.to_s
@@ -15,9 +28,19 @@ def self.build_from_hash(engine, attributes, default_table)
table = Arel::Table.new(table_name, engine)
end
- build(table[column.to_sym], value)
+ if rk = find_reflection_key(column, engine, value)
+ if rk[:foreign_type]
+ queries << build(table[rk[:foreign_type]], value.class.base_class)
+ end
+
+ column = rk[:foreign_key]
+ end
+
+ queries << build(table[column.to_sym], value)
end
- end.flatten
+ end
+
+ queries
end
def self.references(attributes)
@@ -31,6 +54,27 @@ def self.references(attributes)
end.compact
end
+ # Find the foreign key when using queries such as:
+ # Post.where(:author => author)
+ #
+ # For polymorphic relationships, find the foreign key and type:
+ # PriceEstimate.where(:estimate_of => treasure)
+ def self.find_reflection_key(parent_column, model, value)
+ # value must be an ActiveRecord object
+ return nil unless value.class < Model::Tag
+
+ if reflection = model.reflections[parent_column.to_sym]
+ if reflection.options[:polymorphic]
+ {
+ :foreign_key => reflection.foreign_key,
+ :foreign_type => reflection.foreign_type
+ }
+ else
+ { :foreign_key => reflection.foreign_key }
+ end
+ end
+ end
+
private
def self.build(attribute, value)
case value
View
18 activerecord/lib/active_record/relation/query_methods.rb
@@ -340,6 +340,24 @@ def bind!(value)
# User.where({ created_at: (Time.now.midnight - 1.day)..Time.now.midnight })
# # SELECT * FROM users WHERE (created_at BETWEEN '2012-06-09 07:00:00.000000' AND '2012-06-10 07:00:00.000000')
#
+ # In the case of a belongs_to relationship, an association key can be used
+ # to specify the model if an ActiveRecord object is used as the value.
+ #
+ # author = Author.find(1)
+ #
+ # # The following queries will be equivalent:
+ # Post.where(:author => author)
+ # Post.where(:author_id => author)
+ #
+ # This also works with polymorphic belongs_to relationships:
+ #
+ # treasure = Treasure.create(:name => 'gold coins')
+ # treasure.price_estimates << PriceEstimate.create(:price => 125)
+ #
+ # # The following queries will be equivalent:
+ # PriceEstimate.where(:estimate_of => treasure)
+ # PriceEstimate.where(:estimate_of_type => 'Treasure', :estimate_of_id => treasure)
+ #
# === Joins
#
# If the relation is the result of a join, you may create a condition which uses any of the
View
70 activerecord/test/cases/relation/where_test.rb
@@ -1,9 +1,77 @@
require "cases/helper"
+require 'models/author'
+require 'models/price_estimate'
+require 'models/treasure'
require 'models/post'
module ActiveRecord
class WhereTest < ActiveRecord::TestCase
- fixtures :posts
+ fixtures :posts, :authors
+
+ def test_belongs_to_shallow_where
+ author = Post.first.author
+ query_with_id = Post.where(:author_id => author)
+ query_with_assoc = Post.where(:author => author)
+
+ assert_equal query_with_id.to_sql, query_with_assoc.to_sql
+ end
+
+ def test_belongs_to_nested_where
+ author = Post.first.author
+ query_with_id = Author.where(:posts => {:author_id => author}).joins(:posts)
+ query_with_assoc = Author.where(:posts => {:author => author}).joins(:posts)
+
+ assert_equal query_with_id.to_sql, query_with_assoc.to_sql
+ end
+
+ def test_polymorphic_shallow_where
+ treasure = Treasure.create(:name => 'gold coins')
+ treasure.price_estimates << PriceEstimate.create(:price => 125)
+
+ query_by_column = PriceEstimate.where(:estimate_of_type => 'Treasure', :estimate_of_id => treasure)
+ query_by_model = PriceEstimate.where(:estimate_of => treasure)
+
+ assert_equal query_by_column.to_sql, query_by_model.to_sql
+ end
+
+ def test_polymorphic_sti_shallow_where
+ treasure = HiddenTreasure.create!(:name => 'gold coins')
+ treasure.price_estimates << PriceEstimate.create!(:price => 125)
+
+ query_by_column = PriceEstimate.where(:estimate_of_type => 'Treasure', :estimate_of_id => treasure)
+ query_by_model = PriceEstimate.where(:estimate_of => treasure)
+
+ assert_equal query_by_column.to_sql, query_by_model.to_sql
+ end
+
+ def test_polymorphic_nested_where
+ estimate = PriceEstimate.create :price => 125
+ treasure = Treasure.create :name => 'Booty'
+
+ treasure.price_estimates << estimate
+
+ query_by_column = Treasure.where(:price_estimates => {:estimate_of_type => 'Treasure', :estimate_of_id => treasure}).joins(:price_estimates)
+ query_by_model = Treasure.where(:price_estimates => {:estimate_of => treasure}).joins(:price_estimates)
+
+ assert_equal treasure, query_by_column.first
+ assert_equal treasure, query_by_model.first
+ assert_equal query_by_column.to_a, query_by_model.to_a
+ end
+
+ def test_polymorphic_sti_nested_where
+ estimate = PriceEstimate.create :price => 125
+ treasure = HiddenTreasure.create!(:name => 'gold coins')
+ treasure.price_estimates << PriceEstimate.create!(:price => 125)
+
+ treasure.price_estimates << estimate
+
+ query_by_column = Treasure.where(:price_estimates => {:estimate_of_type => 'Treasure', :estimate_of_id => treasure}).joins(:price_estimates)
+ query_by_model = Treasure.where(:price_estimates => {:estimate_of => treasure}).joins(:price_estimates)
+
+ assert_equal treasure, query_by_column.first
+ assert_equal treasure, query_by_model.first
+ assert_equal query_by_column.to_a, query_by_model.to_a
+ end
def test_where_error
assert_raises(ActiveRecord::StatementInvalid) do
View
3  activerecord/test/models/treasure.rb
@@ -6,3 +6,6 @@ class Treasure < ActiveRecord::Base
accepts_nested_attributes_for :looter
end
+
+class HiddenTreasure < Treasure
+end
View
1  activerecord/test/schema/schema.rb
@@ -693,6 +693,7 @@ def create_table(*args, &block)
create_table :treasures, :force => true do |t|
t.column :name, :string
+ t.column :type, :string
t.column :looter_id, :integer
t.column :looter_type, :string
end
View
7 guides/source/active_record_querying.textile
@@ -465,6 +465,13 @@ The field name can also be a string:
Client.where('locked' => true)
</ruby>
+In the case of a belongs_to relationship, an association key can be used to specify the model if an ActiveRecord object is used as the value. This method works with polymorphic relationships as well.
+
+<ruby>
+Post.where(:author => author)
+Author.joins(:posts).where(:posts => {:author => author})
+</ruby>
+
NOTE: The values cannot be symbols. For example, you cannot do +Client.where(:status => :active)+.
h5(#hash-range_conditions). Range Conditions

1 comment on commit 3da275c

@henrik

Awesome. Just looked into adding this.

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