title: Update multiple field values matching a condition in InfluxDB
body: <p>In an InfluxDB measurement, how can the field values of points matching a query be updated? Is this still <a href="https://github.com/influxdata/influxdb/issues/2575" rel="nofollow noreferrer">not easily doable as of v1.6</a>?</p>
  
  <p>As the example in that GitHub ticket suggested, what's the cleanest way of achieving something like this?</p>
  
  <pre><code>UPDATE access_log SET username='something' WHERE mac='xxx'
  </code></pre>
  
  <p>Anything better than driving it all from the client by <a href="https://docs.influxdata.com/influxdb/v1.6/troubleshooting/frequently-asked-questions/#how-does-influxdb-handle-duplicate-points" rel="nofollow noreferrer">updating individual points</a>?</p>