Time series query broken

[jzhao62]

Bug description

• the query used to generate time series data some times needs be explicitly casted as timestamp, in order to be used in Postgres

How to reproduce the bug

1. dump attached data to a a connected Postgres
2. mark the timestamp as Temporal data
3. create any time based chart and examine the auto generated sql
   time-series-data.csv

Screenshots/recordings

Superset version

master / latest-dev

Python version

3.9

Node version

16

Browser

Chrome

Additional context

No response

Checklist

• I have searched Superset docs and Slack and didn't find a solution to my problem.
• I have searched the GitHub issue tracker and didn't find a similar bug report.
• I have checked Superset's logs for errors and if I found a relevant Python stacktrace, I included it here as text in the "additional context" section.

[zhaoyongjie]

Hey @jzhao62, there is no column typing convert logic in current time grain expression so the TIMESTAMP column should have to be offered. The quick and dirty workaround that is to create a computed column in Superset dataset and apply the computed column as time column for your use case.

[jzhao62]

hey @zhaoyongjie thanks, i dont know if this situation applies to all time series data or not. If we explicilty cast the timestamp when generating sql on UI, would it be a problem ?

[zhaoyongjie]

@jzhao62 I totally agree with you. Ideally, the explicit typing conversion should be applied on the temporal column if explicitly defined a column as datetime/date/timestamp.