Make sure these boxes are checked before submitting your issue - thank you!
### Superset version
### Expected results
I add a metric and it is appended to query and displayed on graph
### Actual results
Instead, it adds ONLY count() with different names
In query it looks as
```
SELECT toStartOfDay(toDateTime(tx_time)) AS __timestamp,
count() AS "COUNT_DISTINCT(tx_hash)",
```
instead of
```
SELECT toStartOfDay(toDateTime(tx_time)) AS __timestamp,
COUNT_DISTINCT(tx_hash) AS my_metric_XXX,
```
### Steps to reproduce
Add a metric to a time series graph as shown on picture attached
<img width="595" alt="mymetri"
src="https://user-images.githubusercontent.com/1385046/46603771-cde97a80-cafc-11e8-8221-2d77953e971c.png";>
[ Full content available at:
https://github.com/apache/incubator-superset/issues/6057 ]
This message was relayed via gitbox.apache.org for [email protected]
![https://user-images.githubusercontent.com/1385046/46603771-cde97a80-cafc-11e8-8221-2d77953e971c.png"](https://user-images.githubusercontent.com/1385046/46603771-cde97a80-cafc-11e8-8221-2d77953e971c.png"){kind=link}