新增issue 关联 修复pm工作项被删除后 关联项依然还存在的问题

app/models/issue.rb

@@ -94,6 +94,7 @@ class Issue < ApplicationRecord
   has_many :attach_pull_requests, through: :pull_attached_issues, source: :pull_request
   # PM 关联工作项目
   has_many :pm_links, as: :linkable, dependent: :destroy
+  has_many :be_pm_links,as: :be_linkable, dependent: :destroy
   belongs_to :changer, class_name: 'User', foreign_key: :changer_id, optional: true
 
   scope :issue_includes, ->{includes(:user)}

app/models/pm_link.rb

@@ -18,8 +18,9 @@
 
 class PmLink < ApplicationRecord
   belongs_to :linkable, polymorphic: true
+  belongs_to :be_linkable, polymorphic: true
 
-  def be_linkable
-    be_linkable_type.constantize.find be_linkable_id
-  end
+  # def be_linkable
+  #   be_linkable_type.constantize.find be_linkable_id
+  # end
 end