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.

1 files changed, 13 insertions, 0 deletions

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,