ActiveRecord Cross-DB transactions

gistfile1.rb

# AR transactions wrap a block of code, issuing a rollback if any errors are raised,
# returning result of block if no errors.
#(note: this gist makes use of SecondBase https://github.com/customink/secondbase)
AR = ActiveRecord::Base

AR.transaction { 14 } #=> 14

# Errors are propagated...
AR.transaction { raise } #=> RuntimeError

# ...except ActiveRecord::Rollback errors
AR.transaction { raise ActiveRecord::Rollback } #=> nil

# --
# What does this mean cross-db??
# --

# We can nest transactions!
AR.transaction {