4 files changed, 17 insertions, 1 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
index 6eb59cc398..9371d6f992 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
@@ -18,6 +18,12 @@ module ActiveRecord
         end
       end
 
+      # This is used in the StatementCache object. It returns an object that
+      # can be used to query the database repeatedly.
+      def cacheable_query(arel) # :nodoc:
+        ActiveRecord::StatementCache.query visitor, arel.ast
+      end
+
       # Returns an ActiveRecord::Result instance.
       def select_all(arel, name = nil, binds = [])
         if arel.is_a?(Relation)
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 11b28a4858..ea81cf1736 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -90,6 +90,8 @@ module ActiveRecord
         end
       end
 
+      attr_reader :prepared_statements
+
       def initialize(connection, logger = nil, pool = nil) #:nodoc:
         super()
 
@@ -104,6 +106,10 @@ module ActiveRecord
         @prepared_statements = false
       end
 
+      def bind_substitution_visitor
+        @bind_sub_visitor ||= visitor.dup.extend(Arel::Visitors::BindVisitor)
+      end
+
       def valid_type?(type)
         true
       end
diff --git a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
index b07b0cb826..69c2a361ee 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
@@ -44,6 +44,10 @@ module ActiveRecord
         configure_connection
       end
 
+      def cacheable_query(arel)
+        ActiveRecord::StatementCache.partial_query visitor, arel.ast
+      end
+
       MAX_INDEX_LENGTH_FOR_UTF8MB4 = 191
       def initialize_schema_migrations_table
         if @config[:encoding] == 'utf8mb4'
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index 3c5f7a981e..1e299f12cd 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -273,7 +273,7 @@ module ActiveRecord
 
       def explain(arel, binds = [])
         sql = "EXPLAIN QUERY PLAN #{to_sql(arel, binds)}"
-        ExplainPrettyPrinter.new.pp(exec_query(sql, 'EXPLAIN', binds))
+        ExplainPrettyPrinter.new.pp(exec_query(sql, 'EXPLAIN', []))
       end
 
       class ExplainPrettyPrinter