title: InfluxDB sum returned values with same time
body: <p>I'm trying to retrieve the sum of same values that has the same timestamp.</p>
  <p>My query is</p>
  <pre><code>SELECT value FROM dashboards WHERE time &gt;= '2021-03-07T00:00:00Z' AND time &lt;= '2021-03-09T00:00:00Z'
  </code></pre>
  <p>My returned values are</p>
  <pre><code>time                 value
  ----                 -----
  2021-03-07T00:00:00Z 1
  2021-03-07T00:00:00Z 1
  2021-03-07T00:00:00Z 1
  2021-03-08T00:00:00Z 2
  2021-03-08T00:00:00Z 2
  2021-03-08T00:00:00Z 2
  2021-03-09T00:00:00Z 3
  2021-03-09T00:00:00Z 3
  2021-03-09T00:00:00Z 3
  </code></pre>
  <p>How can I change my query the result will be</p>
  <pre><code>time                 sum
  ----                 -----
  2021-03-07T00:00:00Z 3
  2021-03-08T00:00:00Z 6
  2021-03-09T00:00:00Z 9
  </code></pre>