viz tries to convert to number for a calculated (db function) column which is string

[zyclonite]

Superset version

0.25.5

Expected results

Table View shows my query data for the following clickhouse (sqlalchemy) query

SELECT EventID AS EventID,
       COUNT(*) AS count,
       dictGetString('events', 'Name', toUInt64(EventID)) AS EventName,
       sum(Value) AS TotalValue,
FROM production.fact_game
WHERE EventID == 1000
GROUP BY EventID
ORDER BY TotalValue DESC
LIMIT 50000;

Actual results

Unable to parse string "EventNameABC" at position 0

is displayed with the following stacktrage

Traceback (most recent call last):
  File "pandas/_libs/src/inference.pyx", line 1125, in pandas._libs.lib.maybe_convert_numeric
ValueError: Unable to parse string "EventNameABC"

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/superset/viz.py", line 364, in get_df_payload
    df = self.get_df(query_obj)
  File "/usr/local/lib/python3.6/site-packages/superset/viz.py", line 187, in get_df
    self.df_metrics_to_num(df, query_obj.get('metrics') or [])
  File "/usr/local/lib/python3.6/site-packages/superset/viz.py", line 199, in df_metrics_to_num
    df[col] = pd.to_numeric(df[col])
  File "/usr/local/lib/python3.6/site-packages/pandas/core/tools/numeric.py", line 133, in to_numeric
    coerce_numeric=coerce_numeric)
  File "pandas/_libs/src/inference.pyx", line 1158, in pandas._libs.lib.maybe_convert_numeric
ValueError: Unable to parse string "EventNameABC" at position 0

Potential cause

could be related to the following PR/FIX #4726

[rumbin]

Maybe unrelated, but does the query really work in other clients? To me the EventName column does not look like an aggregation function (dictGetString). I.e., doesn't it need to be in the group by clause?
I'm not experienced with Clickhouse, though...

[zyclonite]

it was not changed since we upgraded from a 0.23.x version... so yes...
the function is no aggregation function, it's simply a lookup in an inmemory map, translating an id to a name

[zyclonite]

maybe fixed with #5176 ?

[stale]

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