ADD a column closed_issues_count to table projects

db/migrate/20200521090205_add_closed_issues_count_to_projects.rb

@@ -0,0 +1,11 @@
+class AddClosedIssuesCountToProjects < ActiveRecord::Migration[5.2]
+  def change
+    add_column :projects, :closed_issues_count, :integer, default: 0
+
+    projects = Project.joins(:issues).where('status_id = 5').select("projects.id, count('issues.id')  as closed_issues_count").group("projects.id")
+    projects.each do |pro|
+      project = Project.find pro.id
+      project.update_column(:closed_issues_count, pro.closed_issues_count) if project.closed_issues_count == 0
+    end
+  end
+end