Merge pull request #41419 from smartygus/activerecord-findermethod-in…

…clude-with-having

Fix #41417 Handle Relations with having referencing aliased selects in #include?

activerecord/CHANGELOG.md

@@ -1,3 +1,34 @@
+*   Skip optimised #exist? query when #include? is called on a relation
+    with a having clause
+
+    Relations that have aliased select values AND a having clause that
+    references an aliased select value would generate an error when
+    #include? was called, due to an optimisation that would generate
+    call #exists? on the relation instead, which effectively alters
+    the select values of the query (and thus removes the aliased select
+    values), but leaves the having clause intact. Because the having
+    clause is then referencing an aliased column that is no longer
+    present in the simplified query, an ActiveRecord::InvalidStatement
+    error was raised.
+
+    An sample query affected by this problem:
+
+    ```ruby
+    Author.select('COUNT(*) as total_posts', 'authors.*')
+          .joins(:posts)
+          .group(:id)
+          .having('total_posts > 2')
+          .include?(Author.first)
+    ```
+
+    This change adds an addition check to the condition that skips the
+    simplified #exists? query, which simply checks for the presence of
+    a having clause.
+
+    Fixes #41417
+
+    *Michael Smart*
+
 *   Increment postgres prepared statement counter before making a prepared statement, so if the statement is aborted
     without Rails knowledge (e.g., if app gets kill -9d during long-running query or due to Rack::Timeout), app won't end
     up in perpetual crash state for being inconsistent with Postgres.

activerecord/lib/active_record/relation/finder_methods.rb

@@ -352,7 +352,7 @@ def exists?(conditions = :none)
     # compared to the records in memory. If the relation is unloaded, an
     # efficient existence query is performed, as in #exists?.
     def include?(record)
-      if loaded? || offset_value || limit_value
+      if loaded? || offset_value || limit_value || having_clause.any?
         records.include?(record)
       else
         record.is_a?(klass) && exists?(record.id)

activerecord/test/cases/finder_test.rb

@@ -412,6 +412,15 @@ def test_include_on_unloaded_relation_with_limit
     assert_equal true,  Customer.order(id: :desc).limit(2).include?(mary)
   end
 
+  def test_include_on_unloaded_relation_with_having_referencing_aliased_select
+    skip if current_adapter?(:PostgreSQLAdapter)
+    bob = authors(:bob)
+    mary = authors(:mary)
+
+    assert_equal false, Author.select("COUNT(*) as total_posts", "authors.*").joins(:posts).group(:id).having("total_posts > 2").include?(bob)
+    assert_equal true, Author.select("COUNT(*) as total_posts", "authors.*").joins(:posts).group(:id).having("total_posts > 2").include?(mary)
+  end
+
   def test_include_on_loaded_relation_with_match
     customers = Customer.where(name: "David").load
     david     = customers(:david)