12:32:12 SQL> select * from tcn;AAA BBB ---------- --------- a 1 b 1 b 1 b 1 c 1 d 2 d 5 d 3 d 6 d 11 a 2 a -1 b -1 b 15 c -1 e 1 e 2 e 123.45679 e 1234.5679已选择19行。实际:260 12:32:22 SQL> select aaa,max(bbb) b from tcn group by aaa order by b;AAA B ---------- --------- c 1 a 2 d 11 b 15 e 1234.5679实际:10012:33:30 SQL> select * from(select aaa,max(bbb) b from tcn group by aaa order by b) where rownum<5;AAA B ---------- --------- c 1 a 2 d 11 b 15实际:91 12:33:56 SQL>
select * from (select id,rank() over (partition by id order by time desc) num from job order by time desc) where num=1;
select rownum rm,a.* from (select id,rank() over (partition by id order by time desc) num from job order by time desc) a where num=1 and rm<11
select * from ( select Comid, max(time) as lasttime from job group by Comid order by lasttime desc ) where rownum < 11
---------- ---------
a 1
b 1
b 1
b 1
c 1
d 2
d 5
d 3
d 6
d 11
a 2
a -1
b -1
b 15
c -1
e 1
e 2
e 123.45679
e 1234.5679已选择19行。实际:260
12:32:22 SQL> select aaa,max(bbb) b from tcn group by aaa order by b;AAA B
---------- ---------
c 1
a 2
d 11
b 15
e 1234.5679实际:10012:33:30 SQL> select * from(select aaa,max(bbb) b from tcn group by aaa order by b) where rownum<5;AAA B
---------- ---------
c 1
a 2
d 11
b 15实际:91
12:33:56 SQL>