Rails 4关系问题，登录时

我不确定在尝试登录时遇到此错误会发生什么变化：

ERROR: relation "tags" does not exist LINE 1: SELECT DISTINCT "tags".* FROM "tags" INNER JOIN "taggings" O... 

标签模型：

 class Tag < ActiveRecord::Base attr_accessor :unread_count, :user_feeds has_many :taggings has_many :feeds, through: :taggings end 

标记模型：

 class Tagging < ActiveRecord::Base belongs_to :tag belongs_to :feed belongs_to :user end 

和用户关系：

 class User < ActiveRecord::Base has_one :coupon has_many :subscriptions, dependent: :delete_all has_many :feeds, through: :subscriptions has_many :entries, through: :feeds has_many :imports, dependent: :destroy has_many :billing_events, as: :billable, dependent: :delete_all has_many :taggings, dependent: :delete_all has_many :tags, through: :taggings has_many :sharing_services, dependent: :delete_all has_many :unread_entries, dependent: :delete_all has_many :starred_entries, dependent: :delete_all has_many :saved_searches, dependent: :delete_all has_many :actions, dependent: :destroy belongs_to :plan end 

这个错误是新的，在我尝试安装intercom.io gem后就出现了。 我删除了gem，做了一个gem清理，重置db并仍然出现同样的错误。

不确定发生了什么，如果有人有任何建议我会很感激。

Answer 1

检查丢失的表，这就是问题所在。