Imagine you have a table like
And you want to calculate, per day, the
sum(amount) of previous and following days.
For example, for the day
2020-01-05 you have to calculate
sumIf(amount, ts < '2020-01-05') and
sumIf(amount, ts >= '2020-01-05')
I think there are many ways to do it but this works:
Check out this snapshot for a step-by-step explanation of what’s going on here.
I think a way to exploit that values for each day don’t need to be calculated every time for each day using a nice function, arrayCumSum, plus some other array magic.
Check this out for a step-by-step explanation.
I feel there should be an easier way but that’s just a feeling.