diff --git a/activerecord/lib/active_record/transactions.rb b/activerecord/lib/active_record/transactions.rb
index 75b2460cf7710dacf4f68fc196819e3edc00f98d..b9def513635fe6aa06b7b784bc7f54ac6377d156 100644
--- a/activerecord/lib/active_record/transactions.rb
+++ b/activerecord/lib/active_record/transactions.rb
@@ -25,7 +25,7 @@ def self.included(base)
# have a number of statements that must be executed together or not at all.
# Example:
#
- # transaction do
+ # ActiveRecord::Base.transaction do
# david.withdrawal(100)
# mary.deposit(100)
# end
@@ -40,7 +40,9 @@ def self.included(base)
#
# Though the transaction class method is called on some Active Record class,
# the objects within the transaction block need not all be instances of
- # that class.
+ # that class. This is because transactions are per-database connection, not
+ # per-model.
+ #
# In this example a Balance record is transactionally saved even
# though transaction is called on the Account class:
#
@@ -49,6 +51,14 @@ def self.included(base)
# account.save!
# end
#
+ # Note that the +transaction+ method is also available as a model instance
+ # method. For example, you can also do this:
+ #
+ # balance.transaction do
+ # balance.save!
+ # account.save!
+ # end
+ #
# == Transactions are not distributed across database connections
#
# A transaction acts on a single database connection. If you have
@@ -95,6 +105,7 @@ def transaction(&block)
end
end
+ # See ActiveRecord::Transactions::ClassMethods for detailed documentation.
def transaction(&block)
self.class.transaction(&block)
end
@@ -131,6 +142,9 @@ def rollback_active_record_state!
# Executes +method+ within a transaction and captures its return value as a
# status flag. If the status is true the transaction is committed, otherwise
# a ROLLBACK is issued. In any case the status flag is returned.
+ #
+ # This method is available within the context of an ActiveRecord::Base
+ # instance.
def with_transaction_returning_status(method, *args)
status = nil
transaction do