FIX: Add unique index to user_notes_count

db/migrate/20200120140900_add_user_notes_count_index.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+class AddUserNotesCountIndex < ActiveRecord::Migration[5.2]
+  def up
+    execute <<~SQL
+      DELETE
+        FROM user_custom_fields a
+       USING user_custom_fields b
+       WHERE a.name = 'user_notes_count'
+         AND a.name = b.name
+         AND a.id > b.id
+    SQL
+
+    add_index :user_custom_fields,
+      [:name, :user_id],
+      unique: true,
+      name: :idx_user_custom_fields_user_notes_count,
+      where: "name = 'user_notes_count'"
+  end
+
+  def down
+    remove_index :user_custom_fields, name: :idx_user_custom_fields_user_notes_count
+  end
+end