The seconds format specifier is wrong when outputting to CSV

[Blufe]

Issue Summary

The seconds format specifier is wrong when outputting to CSV.

Steps to Reproduce

1. Specify "HH:mm:ss.SSS" for Time Format.
2. Execute a query that uses Time Format (eg. SELECT CURRENT_TIMESTAMP() in BigQuery).
3. Download CSV file.

Seconds will not be printed, unix time of the date-time data will be printed.
For example, "2020-05-15T19:34:36.664" will output "2020-05-15T19:34:1589538876664".

Technical details:

• Redash Version: 8.0.2
• Browser/OS: redash/redash:8.0.2.b37747
• How did you install Redash:

[susodapop]

This can probably be fixed along with #4820.

[arikfr]

The bug is here:

redash/redash/serializers/query_result.py

Lines 11 to 20 in b117485

	def _convert_format(fmt):
	return (
	fmt.replace("DD", "%d")
	.replace("MM", "%m")
	.replace("YYYY", "%Y")
	.replace("YY", "%y")
	.replace("HH", "%H")
	.replace("mm", "%M")
	.replace("ss", "%s")
	)

It translates ss to %s, which seems to be the unix timestamp... It also ignores .SSS.

[chulucninh09]

Just want to confirm, according to python docs here, the above code should be changed to

 def _convert_format(fmt): 
     return ( 
         fmt.replace("DD", "%d") 
         .replace("MM", "%m") 
         .replace("YYYY", "%Y") 
         .replace("YY", "%y") 
         .replace("HH", "%H") 
         .replace("mm", "%M") 
         .replace("ss", "%S") 
         .replace("SSS", "%f")
     ) 

However, the string will be fixed at 6-digit microsecond, not 3-digit millisecond as the following screenshot

If you consider this behavior is not harmful to other functions, I can implement it and make PR.

[arikfr]

If you consider this behavior is not harmful to other functions, I can implement it and make PR.

Considering it currently prints the Unix timestamp, having 6 digits instead of 3 should be a great step forward ;-)

A PR will be appreciated. Thanks!

[kravets-levko]

However, the string will be fixed at 6-digit microsecond, not 3-digit millisecond as the following screenshot

I guess you can just cut off last three digits after formatting and it will work just fine

[arikfr]

@kravets-levko but then you need to know when microseconds are used or not.. easier to leave as is.

[chulucninh09]

However, the string will be fixed at 6-digit microsecond, not 3-digit millisecond as the following screenshot

I guess you can just cut off last three digits after formatting and it will work just fine

cutting a string after formatting needs extra implementation. I don't think we should do that way. I will stick with 6-digit solution and make a PR