Question

I have a table that has a processed_timestamp column — if a record has been processed then that field contains the datetime it was processed, otherwise it is null.

I want to write a query that returns two rows:

NULL        xx -- count of records with null timestamps NOT NULL    yy -- count of records with non-null timestamps 

Is that possible?

Update: The table is quite large, so efficiency is important. I could just run two queries to calculate each total separately, but I want to avoid hitting the table twice if I can avoid it.

Answer 1

Oracle:

group by nvl2(field, ‘NOT NULL’, ‘NULL’)