问一个查询语句是什么含义。
if object_id('#t') is not null drop table #t
go
create table #t(pct numeric(12,2),rn int)
insert into #t values(95.77,1);
insert into #t values(4.23,2);
insert into #t values(0,3)
select a.pct,a.rn,sum(b.pct) as run_pct
from #t a join #t b on b.rn<=a.rn
group by a.pct,a.rn
having sum(b.pct)-a.pct<=80
想请问一下having sum(b.pct)-a.pct<=80 这个使用了一个临界值,那么这一句具体筛选的是什么?我有点搞不懂。