Oracle中的SQL,得到表中前10条记录怎么写?
select * from
(Select * from myTable where userId=10 order by CreateTime Desc )t
where rownum<=10
select * from
(Select * from myTable where userId=10 order by CreateTime Desc )t
where rownum<=10
调试欢乐多
select * from table order by dbms_random.value) where rownum<=10
select * from mytable order by dbms_random.value) where rownum<=10
不好意思呀,我怎么看不懂呀,有人帮我解释一下吗?
from后面可以跟一个记录集?
dbms_random.value是 mytable的一个字段吗?以它排序有什么用意?
rownum又是什么呀?
我初学呀,大家别笑我,我可以给你们分的,我分很多的。
SQL> select * from zyz2;
ID P1 P2
---------- ---------- ----------
1 211 212
2 12 14
4 241 242
2 145
1 11
3 17 26 rows selected.Elapsed: 00:00:00.50
SQL> select id,p1,p2 from (select zyz2.*,dbms_random.random num from zyz2 order
by num) where rownum<3; ID P1 P2
---------- ---------- ----------
2 12 14
1 211 212Elapsed: 00:00:00.30
SQL> select id,p1,p2 from (select zyz2.*,dbms_random.random num from zyz2 order
by num) where rownum<3; ID P1 P2
---------- ---------- ----------
3 17 2
2 12 14
8i以上
select * from (select * from ur_table order by sys_guid()) where rownum<n;
select * from (select * from ur_table order by dbms_random.value) where rownum<n;
dbms_random.value(min,max) --从min到max之间取值