title: Summing two columns at row level
body: <p>Quick question. I have a query which outputs results that look a bit like this:</p>
  <pre><code>Customer_ID | Measure_1 | Measure_2
  ------------|-----------|----------
  111         | 1         | 2
  222         | 3         | 4
  333         | 5         | 0
  444         | 0         | 6
  </code></pre>
  <p>I want to add together the values of measure_1 and measure_2 for each customer, so that the results look like this:</p>
  <pre><code>Customer_ID | Total
  ------------|------
  111         | 3
  222         | 7
  333         | 5
  444         | 6
  </code></pre>
  <p>Does anyone know how to do this please?</p>