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我有以下型号:如何对存储在其他模型中的属性模型执行查询?
class Constraint < ActiveRecord::Base
belongs_to :constraint_category
end
class ConstraintCategory < ActiveRecord::Base
has_many :constraints
end
该机型具有这些属性(从DB/schema.rb):
create_table "constraint_categories", :force => true do |t|
t.string "value"
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
t.boolean "active"
end
create_table "constraints", :force => true do |t|
t.string "phrase"
t.integer "constraint_category_id", :limit => 255
t.boolean "active"
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
end
我想创建一个查找所有约束的查询,其中“活动“属性为”真“,”约束_类别。值“为”名词“。
想得到那里的任何建议。
谢谢!这工作。 –
更简洁一点Constraint.joins(:constraint_category).where(:active => true,:constraint_category => {:value =>'Noun'}) – bcd