Rails 3 active record 根据boolean字段删除

  Post.delete_all("person_id = 5 AND (category = 'Something' OR category = 'Else')")
  Post.delete_all(["person_id = ? AND (category = ? OR category = ?)", 5, 'Something', 'Else'])

几个基本的用法

  # Update all billing objects with the 3 different attributes given
  Billing.update_all( "category = 'authorized', approved = 1, author = 'David'" )

  # Update records that match our conditions
  Billing.update_all( "author = 'David'", "title LIKE '%Rails%'" )

  # Update records that match our conditions but limit it to 5 ordered by date
  Billing.update_all( "author = 'David'", "title LIKE '%Rails%'",
                        :order => 'created_at', :limit => 5 )

但是某个字段是boolean时呢

最好

Message.update_all({:read => true}, {:id => user.messages})

然后，字段是null怎么办呢，不好is null的猜，sqllite，mysql 可能不一致

Message.update_all({:read => nil}, {:id => user.messages})

参考了很多APIDOCK 3.0.7给人家一个赞助链接


http://apidock.com/rails/ActionView/Helpers/FormHelper/form_for

http://apidock.com/rails/ActiveRecord/Base/update_all/class