title: DAX: How to count rows with correlations to another row?
body: <p>being new to dax, I am having trouble formulating my question and a solution related to counting rows for question-answer pairs.</p>
  
  <p>the general scenario is a tabular bi model which models surveys having a question and answer pairing where 1 question may have 1 to N response options. The fact table's key data is Respondent, Response. This table references a 'Question Answer' table holding answer details of which Answer is the salient data. this table in turn references the Question table which holds information about the question.</p>
  
  <p>I am trying to solve the query of the form, how many people answered Question X, but did not answer Question Y? in other words, of the people answering Question 1, how many did not answer Question 12?</p>
  
  <p>When a question is not answered, there is no row for the question response in the fact table.</p>
  
  <p>I have been trying to create a measure for the fact table, Survey Response, and believe that it requires some Calculate() operations. A video at <a href="http://msbiacademy.com/?p=3491" rel="nofollow">http://msbiacademy.com/?p=3491</a> has some promising leads, but I can't quite get over the hump, in part because it creates a duplicate table for product subcategory and i am not sure if that is through importing the table twice, and because it uses UserRelationship. So perhaps in my case I would import Question twice but it doesn't make sense. I am not using slicers so that may be part of the difference.</p>
  
  <p>the measure is directed primary to the top level entity Survey.</p>
  
  <p>the environment vs 2013 tabular bi model, sql server 2012, excel 2013.</p>