OracleµÄ¼¸¸ö¼¯ºÏ²Ù×÷
Union£¬¶ÔÁ½¸ö½á¹û¼¯½øÐв¢¼¯²Ù×÷£¬²»°üÀ¨Öظ´ÐУ¬Í¬Ê±½øÐÐĬÈϹæÔòµÄÅÅÐò£»
Union All£¬¶ÔÁ½¸ö½á¹û¼¯½øÐв¢¼¯²Ù×÷£¬°üÀ¨Öظ´ÐУ¬²»½øÐÐÅÅÐò£»
Intersect£¬¶ÔÁ½¸ö½á¹û¼¯½øÐн»¼¯²Ù×÷£¬²»°üÀ¨Öظ´ÐУ¬Í¬Ê±½øÐÐĬÈϹæÔòµÄÅÅÐò£»
Minus£¬¶ÔÁ½¸ö½á¹û¼¯½øÐвî²Ù×÷£¬²»°üÀ¨Öظ´ÐУ¬Í¬Ê±½øÐÐĬÈϹæÔòµÄÅÅÐò¡£
¿ÉÒÔÔÚ×îºóÒ»¸ö½á¹û¼¯ÖÐÖ¸¶¨Order by×Ó¾ä¸Ä±äÅÅÐò·½Ê½:
select score,id,name
from student
where id > 2 and id < 7
union
select score,id,name
from student
where id < 4
union
select score,id,name
from student
where id > 8
order by id desc
Ïà¹ØÎĵµ£º
oracle±í¿Õ¼ä²Ù×÷Ïê½â
1
2
3×÷Õߣº À´Ô´£º ¸üÐÂÈÕÆÚ£º2006-01-04
5
6
7½¨Á¢±í¿Õ¼ä
8
9CREATE TABLESPACE data01
10DATAFILE '/ora ......
ÒÔÉÏΪתÔØ,¶àÊý²¢Î´ÑéÖ¤.
ÆäÖÐ,select trunc(sysdate,'dd') from dual,µÃµ½µÄÊÇ: 2009-3-23 ÉÏÎç12:00:00 ,ÓëÏÂÎIJ¢²»Ò»Ñù!
oracle trunc()º¯ÊýµÄÓ÷¨
1.TRUNC(for dates)
TRUNCº¯ÊýΪָ¶¨ÔªËضø½ØÈ¥µÄÈÕÆÚÖµ¡£
Æä¾ßÌåµÄÓï·¨¸ñʽÈçÏ£º
TRUNC£¨date[,fmt]£©
ÆäÖУº
date Ò»¸öÈÕÆÚÖµ
fmt ÈÕÆÚ¸ñʽ£¬¸ÃÈÕÆÚ½« ......
ÓÐÁ½ÖÖº¬ÒåµÄ±í´óС¡£Ò»ÖÖÊÇ·ÖÅä¸øÒ»¸ö±íµÄÎïÀí¿Õ¼äÊýÁ¿£¬¶ø²»¹Ü¿Õ¼äÊÇ·ñ±»Ê¹Ó᣿ÉÒÔÕâÑù²éѯ»ñµÃ×Ö½ÚÊý£º
select segment_name, bytes
from user_segments
where segment_type = 'TABLE';
»òÕß
Select Segment_Name,Sum(bytes)/1024/1024 from User_Extents Group By Segment_Name
ÁíÒ»ÖÖ±íÊ ......
¸ôÀ뼶±ð£¨isoation level£©
¸ôÀ뼶±ð¶¨ÒåÁËÊÂÎñÓëÊÂÎñÖ®¼äµÄ¸ôÀë³Ì¶È¡£
¸ôÀ뼶±ðÓë²¢·¢ÐÔÊÇ»¥ÎªÃ¬¶ÜµÄ£º¸ôÀë³Ì¶ÈÔ½¸ß£¬Êý¾Ý¿âµÄ²¢·¢ÐÔÔ½²î£»¸ôÀë³Ì¶ÈÔ½µÍ£¬Êý¾Ý¿âµÄ²¢·¢ÐÔÔ½ºÃ¡£
ANSI/ISO SQ92±ê×¼¶¨ÒåÁËһЩÊý¾Ý¿â²Ù×÷µÄ¸ôÀ뼶±ð£º
δÌá½»¶Á£¨read uncommitted£©
Ìá½»¶Á£¨read committed£© &n ......
³õѧlinux+oracle£¬²ÉÓõı¾µØÐéÄâ»ú°²×°linuxµÄ·½Ê½£¬°æ±¾ÊÇRed Hat 5£¬Î¨Ò»¸úÐéÄâ»ú°²×°ÆäËûϵͳ²»Í¬µÄÊÇ£º¶¨ÖÆ£¬Ñ¡IDEÓ²ÅÌ£¬·ñÔò°²×°¹ý³ÌÌáʾÕÒ²»µ½Ó²ÅÌʧ°Ü¡£
±¾ÎÄÖصãÊÇOracle°²×°¹ý³Ì£¬°æ±¾ 10.1.0¡£
3¡¢°²×°Ïà¹ØµÄ¿ª·¢°ü£¨rpm°ü£©£º
rpm -q binutils co ......