Migrate Quiz Results Data
This isn't the "Drupal way" to do this, but I accomplished a successful quiz results migration by making a few compromises and doing things in an unorthodox way. If anyone can build upon this and add a new answer with the correct way accomplish, I would be delighted!

The compromise I made was not allowing users to view their old results, just their score. I also decided not to use the certificate and created a view page instead for individual scores to make a certificate that way. (See this SE Post for my issues with Certificate.) This killed 2 birds with 1 stone.

Steps I followed for a successful migration trial on the test website:


Add quiz_node_results table to new database:


mysql&gt; insert into drupal.quiz_node_results (result_id, nid, vid, uid, time_start, time_end, released, score, is_invalid, is_evaluated, time_left) select result_id, nid, vid, uid, time_start, time_end, released, score, is_invalid, is_evaluated, time_left from drupal_web.quiz_node_results;


Replaced NID of quiz results with new quiz nid, run once for each quiz (there were 18 quiz nodes):


mysql&gt; update quiz_node_results set nid = replace (nid, [old quiz node ID], [new quiz ID]);


Removed "view quiz results" from Gradebook view (custom view I built for showing results).


Please comment with foreseeable issues with this method.