ActiveRecord find with join options retrieves object as readonly.
station = Station.find( :first, :joins => :call, :conditions => ["customer_id = ? and date(insurance_expiry_date) = ?", customer.id, insurance_expiry_date ] )
Readonly object cannot modified.
station.update_attributes({ :customer_id => 12 })
should raise following error.
ActiveRecord::ReadOnlyRecord
If you wanted to do write on object then you need to pass following option to find query.
:readonly => false
station = Station.find( :first, :joins => :call, :conditions => ["customer_id = ? and date(insurance_expiry_date) = ?", customer.id, insurance_expiry_date ], :readonly => false )
Josh Software 