From a50eacb03cf3df1d1cbc227ea0115901e0327f1c Mon Sep 17 00:00:00 2001
From: Ryuta Kamizono <kamipo@gmail.com>
Date: Sun, 9 Sep 2018 03:30:45 +0900
Subject: Eager loading/preloading should be worked regardless of large number
of records
Since 213796f, bind params are used for IN clause if enabled prepared
statements.
Unfortunately, most adapter modules have a limitation for # of bind
params (mysql2 65535, pg 65535, sqlite3 250000). So if eager loading
large number of records at once, that query couldn't be sent to the
database.
Since eager loading/preloading queries are auto-generated by Active
Record itself, so it should be worked regardless of large number of
records like as before.
Fixes #33702.
---
.../lib/active_record/relation/predicate_builder.rb | 6 +++++-
.../relation/predicate_builder/array_handler.rb | 9 +++++----
activerecord/test/cases/associations/eager_test.rb | 13 +++++++++++++
activerecord/test/fixtures/citations.yml | 4 ++++
activerecord/test/models/citation.rb | 1 +
activerecord/test/schema/schema.rb | 1 +
6 files changed, 29 insertions(+), 5 deletions(-)
create mode 100644 activerecord/test/fixtures/citations.yml
(limited to 'activerecord')
diff --git a/activerecord/lib/active_record/relation/predicate_builder.rb b/activerecord/lib/active_record/relation/predicate_builder.rb
index f734cd0ad8..cb70b8bcde 100644
--- a/activerecord/lib/active_record/relation/predicate_builder.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder.rb
@@ -57,10 +57,14 @@ module ActiveRecord
end
def build_bind_attribute(column_name, value)
- attr = Relation::QueryAttribute.new(column_name.to_s, value, table.type(column_name))
+ attr = build_query_attribute(column_name, value)
Arel::Nodes::BindParam.new(attr)
end
+ def build_query_attribute(column_name, value)
+ Relation::QueryAttribute.new(column_name.to_s, value, table.type(column_name))
+ end
+
protected
def expand_from_hash(attributes)
return ["1=0"] if attributes.empty?
diff --git a/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
index e5191fa38a..0895b9fba6 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
@@ -21,10 +21,11 @@ module ActiveRecord
when 0 then NullPredicate
when 1 then predicate_builder.build(attribute, values.first)
else
- bind_values = values.map do |v|
- predicate_builder.build_bind_attribute(attribute.name, v)
- end
- attribute.in(bind_values)
+ values.map! do |v|
+ attr = predicate_builder.build_query_attribute(attribute.name, v)
+ attr.value_for_database if attr.boundable?
+ end.compact!
+ values.empty? ? NullPredicate : attribute.in(values)
end
unless nils.empty?
diff --git a/activerecord/test/cases/associations/eager_test.rb b/activerecord/test/cases/associations/eager_test.rb
index a1fba8dc66..ca902131f4 100644
--- a/activerecord/test/cases/associations/eager_test.rb
+++ b/activerecord/test/cases/associations/eager_test.rb
@@ -18,6 +18,7 @@ require "models/job"
require "models/subscriber"
require "models/subscription"
require "models/book"
+require "models/citation"
require "models/developer"
require "models/computer"
require "models/project"
@@ -29,6 +30,18 @@ require "models/sponsor"
require "models/mentor"
require "models/contract"
+class EagerLoadingTooManyIdsTest < ActiveRecord::TestCase
+ fixtures :citations
+
+ def test_preloading_too_many_ids
+ assert_equal Citation.count, Citation.preload(:citations).to_a.size
+ end
+
+ def test_eager_loading_too_may_ids
+ assert_equal Citation.count, Citation.eager_load(:citations).offset(0).size
+ end
+end
+
class EagerAssociationTest < ActiveRecord::TestCase
fixtures :posts, :comments, :authors, :essays, :author_addresses, :categories, :categories_posts,
:companies, :accounts, :tags, :taggings, :people, :readers, :categorizations,
diff --git a/activerecord/test/fixtures/citations.yml b/activerecord/test/fixtures/citations.yml
new file mode 100644
index 0000000000..d31cb8efa1
--- /dev/null
+++ b/activerecord/test/fixtures/citations.yml
@@ -0,0 +1,4 @@
+<% 65536.times do |i| %>
+fixture_no_<%= i %>:
+ id: <%= i %>
+<% end %>
diff --git a/activerecord/test/models/citation.rb b/activerecord/test/models/citation.rb
index 3d786f27eb..cee3d18173 100644
--- a/activerecord/test/models/citation.rb
+++ b/activerecord/test/models/citation.rb
@@ -2,4 +2,5 @@
class Citation < ActiveRecord::Base
belongs_to :reference_of, class_name: "Book", foreign_key: :book2_id
+ has_many :citations
end
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 266e55f682..27c7348f5c 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -160,6 +160,7 @@ ActiveRecord::Schema.define do
create_table :citations, force: true do |t|
t.column :book1_id, :integer
t.column :book2_id, :integer
+ t.references :citation
end
create_table :clubs, force: true do |t|
--
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