I have the following table:
ID Date
-------------------
1 Null
1 1/2/2020
2 Null
2 12/2/2020
3 Null
For every ID which has at least one non-null date, I need to classify as 'accounted'.
Result set should look like below:
id Date AccountFlag
----------------------------
1 Null Accounted
1 1/2/2020 Accounted
2 Null Accounted
2 12/2/2020 Accounted
3 Null Unaccounted
You can use window functions to check if the same id has at least one non-null date, and a case expression to set the flag accordingly. Window aggregate functions come handy for this:
select id, date,
case when max(date) over(partition by id) is not null
then 'Accounted'
ese 'Unaccounted'
end as accountflag
from mytable
max() ignores null values, so it returns null if and only if all values in the partition are null. This would work just the same with min().
