title: Stacking datasets by creating new variables
body: <p>I have two datasets that need to be stacked on top of each-other. Think of them as two subsets of one data-set. The issue is that they have completely different variables other than the &quot;record_id&quot; and one more variable</p>
  <pre><code>ds_app &lt;- data.frame(record_id, a, b, c, d, e, f)
  ds_vo  &lt;- data.frame(record_id, g, h, i, j, k, l , m, n, o, p, q)
  </code></pre>
  <p>Is there an easy way to stack these other than having to create dummy variables that don't exist in the other datasets; variables with assigned NA values.</p>
  <p>Thanks so much!</p>