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eg:
create table dml.cases(
num NUMBER primary key, --ÐòºÅ
name VARCHAR2(50), --°¸ÀýÃû³Æ
intro VARCHAR2(100), --°¸Àý¼ò½é
);
ÏÖÔÚÏ£Íû»ñµÃnum=10 µÄÊý¾Ý ÔÚ°´num ½µÐòÅÅÁкóµÄÅÅÃû£¬Ò²¾ÍÊǵڼ¸¸ö
ÔÙ²¹³ä¸öÎÊÌâ°¡£¬¾ÍÊÇÒª²é°´num ½µÐòÅÅÁеÚÊ®¸öÊý¾ÝÔõôд£¬Ð»Ð»
SQL code:
select rownum rn,t.* from
(select * from dml.cases order by num desc) t
where t.num=10;
²»ÄÜÓÃrownum,ÒòΪrownum±ØÐë°üº¬rownum=1µÄÖµ,·ñÔòÈ¡²»µ½
¿ÉÒÔÓ÷ÖÎöº¯Êýrow_number()°ïÄã½â¾öÎÊÌâ
SQL code:
--µÚ10¸öÊý¾Ý
SELECT *
from (SELECT rownum rn, t.* from (SELECT * from dml.cases ORDER BY num DESC) t)
WHERE rn = 10;
create table dml.cases(
num NUMBER primary key, --ÐòºÅ
name VARCHAR2(50), --°¸ÀýÃû³Æ
intro VARCHAR2(100), --°¸Àý¼ò½é
);
ÔÙ²¹³ä¸öÎÊÌâ°¡£¬¾ÍÊÇÒª²é°´num ½µÐòÅÅÁеÚÊ®¸öÊý¾ÝÔõôд£¬Ð»Ð»
1 select count(*) from dml.cases where num>10;
2 ²¹³äÎÊÌ⣺select * from dml.cases where rowid=10 order by dese;
1 select count(*)+1 from dml.cases where num>10;
2 ²¹³äÎÊÌ⣺select * from dml.cases where rowid=10 order by dese;
ºÃÏñ¶¼Àí½â´íÎÒµÄÒâ˼ÁË£¬µÚÒ»¸öÌû×ÓµÄÕýÈ·´ð°¸£º
select row_number
Ïà¹ØÎÊ´ð£º
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[oracle@linux trace]$ vi alert_orcl.log
MMON started with pid=14, OS id=9089
RESETLOGS after incomplete recovery UNTIL CHANGE 522752
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