title: How do I put variables in Apache Superset?
body: <p>I'd like to use a filter in Apache Superset. However, most examples were to load the results and then apply the filter.</p>
  <p>I want to put this in the middle of Query as a variable.
  All I found was the WHERE condition at the end.</p>
  <p>ex)</p>
  <pre><code>SELECT a AS a , b AS b , c AS c , d AS d
  (
  SELECT a,b,c,d 
  FROM table
  )AS `expr_qry`
  WHERE a = '1' -- filter 
  </code></pre>
  <p>If I make a filter, I brought it to WHERE.</p>
  <p><strong>But what I want is as follows.</strong></p>
  <pre><code>SELECT a,b,c,@var1 as d
  FROM table
  WHERE a = '@var2' 
  </code></pre>
  <p>Put it in like a variable above.
  Is there a way to do this?</p>