I have a table that looks a bit like this:
date | timestamp | predicted_value
2017-10-25| 21758492893 | 0.4
2017-10-25| 21758492917 | 0.3
2017-10-25| 21758493210 | 0.4
2017-10-25| 21758493782 | 0.2
2017-10-25| 21758494903 | 0.1
2017-10-26| 21758492893 | 7.2
....
I'd like to be able to use a single query to get the latest predicted_value for a given date, by timestamp. I.E in my output I want:
date | timestamp | predicted_value
2017-10-25| 21758494903 | 0.1
2017-10-26| 21758494903 | 7.7
....
I think it should go something like this:
Predictions.objects.all().order_by(
'-timestamp'
).values(
'date'
).annotate(
prediction=F('predicted_value')
)
Is this going to work? Will F select the first value found in the aggregation or can I not use it that way?
