Ò׽ؽØÍ¼Èí¼þ¡¢µ¥Îļþ¡¢Ãâ°²×°¡¢´¿ÂÌÉ«¡¢½ö160KB

¸ß¼¶SQL @Oracle

1.¼¯ºÏ²Ù×÷
ѧϰoracle
Öм¯ºÏ²Ù×÷µÄÓйØÓï¾ä£¬
ÕÆÎÕunion,union
all,minus,interestµÄʹÓÃ,Äܹ»ÃèÊö½áºÏÔËË㣬²¢ÇÒÄܹ»½«¶à¸ö²éѯ×éºÏµ½Ò»¸ö²éѯÖÐÈ¥£¬Äܹ»¿ØÖÆÐзµ»ØµÄ˳Ðò¡£
°üº¬¼¯ºÏÔËËãµÄ
²éѯ³ÆÎª¸´ºÏ²éѯ¡£¼û±í¸ñ1-1
±í1-1
Operator         Returns         content
UNION 
       ÓÉÿ¸ö²éѯѡÔñµÄËùÓв»Öظ´µÄÐР         ²¢¼¯²»°üº¬Öظ´Öµ
UNION ALL       
 ÓÉÿ¸ö²éѯѡÔñµÄËùÓеÄÐУ¬°üÀ¨ËùÓÐÖØ¸´µÄÐР        ÍêÈ«²¢¼¯°üº¬Öظ´Öµ
INTERSECT       
 ÓÉÿ¸ö²éѯѡÔñµÄËùÓв»Öظ´µÄÏཻÐР         ½»¼¯
MINUS       
 ÔÚµÚÒ»¸ö²éѯÖУ¬²»ÔÚºóÃæ²éѯÖУ¬²¢ÇÒ½á¹ûÐв»Öظ´          ²î¼¯
ËùÓеļ¯ºÏÔËËãÓëµÈºÅµÄÓÅÏȼ¶Ïàͬ£¬Èç¹ûSQL
Óï¾ä°üº¬¶à¸ö¼¯ºÏÔËËã²¢ÇÒûÓÐÔ²À¨ºÅÃ÷È·µØÖ¸¶¨ÁíÒ»¸ö˳
Ðò£¬Oracle·þÎñÆ÷½«ÒÔ´Ó×óµ½ÓÒµÄ˳Ðò¼ÆËã¡£ÄãÓ¦¸ÃʹÓÃÔ²À¨ºÅÀ´Ã÷È·µØÖ¸¶¨´øÁíÍâµÄ¼¯ºÏÔËËãµÄINTERSECT (Ïཻ) ÔËËã²éѯÖеĸ³ÖµË³Ðò¡£
Union
all ЧÂÊÒ»°ã±Èunion¸ß¡£
1.1.unionºÍunion all
UNION(ÁªºÏ)ÔËËã
UNIONÔËËã·µ»ØËùÓÐÓÉÈÎ
Ò»²éѯѡÔñµÄÐС£ÓÃUNIONÔËËã´Ó¶à±í·µ»ØËùÓÐÐУ¬µ«³ýÈ¥ÈκÎÖØ¸´µÄÐС£
Ô­Ôò :
􀂃±»Ñ¡ÔñµÄÁÐÊý
ºÍÁеÄÊý¾ÝÀàÐͱØÐëÊÇÓëËùÓÐÓÃÔÚ²éѯÖеÄSELECTÓï¾äÒ»Ö¡£ÁеÄÃû×Ö²»±ØÏàͬ¡£
􀂃ÁªºÏÔËËãÔÚËùÓб»Ñ¡ÔñµÄÁÐÉϽø
ÐС£
􀂃ÔÚ×öÖØ¸´¼ì²éµÄʱºò²»ºöÂÔ¿Õ(NULL)Öµ¡£
􀂃INÔËËãÓбÈUNION
ÔËËã¸ßµÄÓÅÏȼ¶¡£
􀂃ÔÚĬÈÏÇé¿öÏ£¬Êä³öÒÔSELECT×Ó¾äµÄµÚÒ»ÁеÄÉýÐòÅÅÐò¡£
È«ÁªºÏ(UNION
ALL)ÔËËã
ÓÃÈ«ÁªºÏÔËËã´Ó¶à¸ö²éѯÖзµ»ØËùÓÐÐС£
Ô­Ôò
􀂃ºÍÁªºÏ²»Í¬£¬Öظ´µÄÐв»±»¹ý
ÂË£¬²¢ÇÒĬÈÏÇé¿öÏÂÊä³ö²»ÅÅÐò¡£
􀂃²»ÄÜʹÓÃDISTINCT¹Ø¼ü×Ö¡£
ʹÓãº
Select
statement union | union all Select statement;
1.2.intersect½»¼¯²Ù×÷
Ïà
½»ÔËËã
ÓÃÏཻÔËËã·µ»Ø¶à¸ö²éѯÖÐËùÓеĹ«¹²ÐС£ ÎÞÖØ¸´ÐС£
Ô­Ôò
&#104870


Ïà¹ØÎĵµ£º

SQLÓï·¨ÓëÃüÁî


SQLÓï·¨ÓëÃüÁî
SELECT Óï¾ä
SELECT[predicate]{*|table.*|[table.]field [,[table.]field2[,...]]} [AS alias1
[,alias2[,...]]]
from tableexpression [,...][IN externaldatabase]
[WHERE...]
[GROUP BY...]
[HAVING...]
[ORDER BY...]
[WITH OWNERACCESS OPTION]
SELECT Óï¾ä°üÀ¨ÏÂÃæ¼¸¸ö²¿·Ö
predicate ......

sqlÓï¾ä²éѯ½á¹ûºÏ²¢union ºÍunion allÓ÷¨

sqlÓï¾ä²éѯ½á¹ûºÏ²¢union ºÍunion allÓ÷¨
 
--ºÏ²¢Öظ´ÐÐ
select * from A
union
select * from B
--²»ºÏ²¢Öظ´ÐÐ
select * from A
union all
select * from B
°´Ä³¸ö×Ö¶ÎÅÅÐò
--ºÏ²¢Öظ´ÐÐ
select *
from (
select * from A
union
select * from B) AS T
order by ×Ö¶ÎÃû
--²»ºÏ²¢Öظ´ÐÐ
sel ......

SQL²éѯÖеÄתÒå×Ö·û ÀÁèÐÇ¿Õ

Èç¹ûÏë²éÕÒ“_cs”½áβµÄµÄÕË»§
select * from [user] where loginname like '%_cs'ÊDz»Ðеģ¬_ ±»ÈÏΪÊÇÈÎÒâµÄ×Ö·û£¬
ËùÒÔÐèҪתÒå×Ö·û£¬ÓÐÁ½ÖÖд·¨£º
select * from [user] where loginname like '%[_]cs'
select * from [user] where loginname like '%/_cs' escape'/'
ͨÅä·ûº¬Òå
%
°üº¬Áã¸ö»ò¸ü¶à×Ö· ......

SQL SERVER 2008 Õý³£°²×°Ê§°ÜºóµÄ¼¯³É°²×°

×î½üÐèÒª²âÊÔÒ»¸öÏîÄ¿, ÐèÒªSQL SERVER 2008, ÔÚ΢ÈíÏÂÔØÆÀ¹À°æºó½øÐа²×°
Öм䷢ÏÖÁËÖÖÖÖ°²×°Ê§°ÜµÄÎÊÌ⣬¶Ô¸Ã¹ý³Ì½øÐÐÁ˼Ǽ£¬Ï£Íû¸øÓöµ½´ËÀàÎÊÌâµÄÅóÓÑÃǹ²Í¬Ì½ÌÖ£¬ÓÐËù°ïÖú£º
1. WINDOWS 2003, WINDOWS 7 ÐÂ×°µÄʱºò¿ÉÐУ¬µ«ÊÇÈç¹ûÓÐɾ³ýºóÖØÐ°²×°ÔòÎÞ·¨Ôٴΰ²×°
2. ¸ù¾ÝÍøÉÏÎÞÊýÏÈÇýµÄʧ°ÜÌáʾ£¬ ½øÐÐÁËÎÞÊýÖØÊÔ£¬ ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ