好问题。我可以想到的一种选择是:
select COALESCE(a, -1) AS a, COALESCE(b, -1) AS b, sum(c)
from <table>
group by COALESCE(a, -1), COALESCE(b, -1) with rollup;
在使用“逐个汇总”时区分NULL。
好问题。我可以想到的一种选择是:
select COALESCE(a, -1) AS a, COALESCE(b, -1) AS b, sum(c)
from <table>
group by COALESCE(a, -1), COALESCE(b, -1) with rollup;