1 files changed, 19 insertions, 7 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 47f2ad9b10..e8ce00d92b 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
@@ -9,15 +9,23 @@ module ActiveRecord
       # Converts an arel AST to SQL
       def to_sql(arel, binds = [])
         if arel.respond_to?(:ast)
-          binds = binds.dup
-          visitor.accept(arel.ast) do
-            quote(*binds.shift.reverse)
-          end
+          collected = visitor.accept(arel.ast, collector)
+          collected.compile(binds.dup, self)
         else
           arel
         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:
+        if prepared_statements
+          ActiveRecord::StatementCache.query visitor, arel.ast
+        else
+          ActiveRecord::StatementCache.partial_query visitor, arel.ast, collector
+        end
+      end
+
       # Returns an ActiveRecord::Result instance.
       def select_all(arel, name = nil, binds = [])
         arel, binds = binds_from_relation arel, binds
@@ -185,7 +193,7 @@ module ActiveRecord
       # * You are creating a nested (savepoint) transaction
       #
       # The mysql, mysql2 and postgresql adapters support setting the transaction
-      # isolation level. However, support is disabled for mysql versions below 5,
+      # isolation level. However, support is disabled for MySQL versions below 5,
       # because they are affected by a bug[http://bugs.mysql.com/bug.php?id=39170]
       # which means the isolation level gets persisted outside the transaction.
       def transaction(options = {})
@@ -219,6 +227,10 @@ module ActiveRecord
         end
       end
 
+      def open_transactions
+        @transaction.number
+      end
+
       def current_transaction #:nodoc:
         @transaction
       end
@@ -326,8 +338,8 @@ module ActiveRecord
       end
 
       # The default strategy for an UPDATE with joins is to use a subquery. This doesn't work
-      # on mysql (even when aliasing the tables), but mysql allows using JOIN directly in
-      # an UPDATE statement, so in the mysql adapters we redefine this to do that.
+      # on MySQL (even when aliasing the tables), but MySQL allows using JOIN directly in
+      # an UPDATE statement, so in the MySQL adapters we redefine this to do that.
       def join_to_update(update, select) #:nodoc:
         key = update.key
         subselect = subquery_for(key, select)