使用动态查找器指定不是null
-
01-10-2019 - |
题
我经常想使用动态发现器来指定不是null。所以…
这起作用:
Widget.find_all_by_color('blue')
这起作用:
Widget.find_all_by_color(nil)
但是我该怎么办
SELECT * FROM `widgets` WHERE `color` IS NOT NULL;
?
解决方案
试试这个:
Widget.all(:conditions => "color IS NOT NULL")
其他提示
两种方式取决于您想要的特定程度:
# in your model
class Widget < ActiveRecord::Base
# first way
named_scope :coloured, {:conditions => ["color IS NOT NULL"]}
# second way
named_scope :not_null, lambda{|*args| (field=args.first ? {:conditions => ["#{field} is not null",field]} : {}) } }
end
# in your controller
@coloured_widgets = Widget.coloured.all # using first way
@coloured_widgets = Widget.not_null(:colour).all # using second way
我希望它有帮助。
干杯
Widget.find(:all, :conditions => "color IS NOT NULL")
不太优雅,但这应该奏效:
Widget.find(:all, :conditions => "'color' IS NOT NULL")
不隶属于 StackOverflow