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

oracle PL/SQL FOR UPDATE Óë FOR UPDATE OFµÄÇø±ð

PL/SQL-FOR UPDATE Óë FOR UPDATE OFµÄÇø±ð
url:http://hi.baidu.com/1413/blog/item/a521251f7e5993c4a686696b.html
Êý¾Ý¿â oracle for update of   ºÍ   for updateÇø±ð    
select * from TTable1 for update Ëø¶¨±íµÄËùÓÐÐУ¬Ö»ÄܶÁ²»ÄÜд
2 select * from TTable1 where pkid = 1 for update Ö»Ëø¶¨pkid=1µÄÐÐ
3 select * from Table1 a join Table2 b on a.pkid=b.pkid for update Ëø¶¨Á½¸ö±íµÄËùÓмǼ
4 select * from Table1 a join Table2 b on a.pkid=b.pkid where a.pkid = 10 for update Ëø¶¨Á½¸ö±íµÄÖÐÂú×ãÌõ¼þµÄÐÐ
5. select * from Table1 a join Table2 b on a.pkid=b.pkid where a.pkid = 10 for update of a.pkid Ö»Ëø¶¨Table1ÖÐÂú×ãÌõ¼þµÄÐÐ
for update ÊǰÑËùÓÐµÄ±í¶¼Ëøµã for update of ¸ù¾Ýof ºó±íµÄÌõ¼þËø¶¨Ïà¶ÔÓ¦µÄ±í
-----------
¹ØÓÚNOWAIT(Èç¹ûÒ»¶¨ÒªÓÃFOR UPDATE£¬ÎÒ¸ü½¨Òé¼ÓÉÏNOWAIT)
µ±ÓÐLOCK³åͻʱ»áÌáʾ´íÎó²¢½áÊøSTATEMENT¶ø²»ÊÇÔÚÄÇÀïµÈ´ý(±ÈÈç:Òª²éµÄÐÐÒѾ­±»ÆäËüÊÂÎñËøÁË,µ±Ç°µÄËøÊÂÎñÓëÖ®³åÍ»,¼ÓÉÏnowait,µ±Ç°µÄÊÂÎñ»á½áÊø»áÌáʾ´íÎó²¢Á¢¼´½áÊø STATEMENT¶ø²»Ôٵȴý).
Èç¹û¼ÓÁËfor updateºó ¸ÃÓï¾äÓÃÀ´Ëø¶¨Ìض¨µÄÐУ¨Èç¹ûÓÐwhere×Ӿ䣬¾ÍÊÇÂú×ãwhereÌõ¼þµÄÄÇЩÐУ©¡£µ±ÕâЩÐб»Ëø¶¨ºó£¬ÆäËû»á»°¿ÉÒÔÑ¡ÔñÕâЩÐУ¬µ«²»Äܸü¸Ä»òɾ³ýÕâЩÐУ¬Ö±µ½¸ÃÓï¾äµÄÊÂÎñ±»commitÓï¾ä»òrollbackÓï¾ä½áÊøÎªÖ¹¡£
ÒòΪFOR   UPDATE×Ó¾ä»ñµÃÁËËø£¬ËùÒÔCOMMIT½«ÊÍ·ÅÕâÐ©Ëø¡£µ±ËøÊÍ·ÅÁË£¬¸ÃÓαê¾ÍÎÞЧÁË¡£


Ïà¹ØÎĵµ£º

Oracle PL/SQLÖÐÈçºÎʹÓÃ%TYPEºÍ%ROWTYPE

¡¡
¡¡¡¡1. ʹÓÃ%TYPE
¡¡¡¡ÔÚÐí¶àÇé¿öÏ£¬PL/SQL±äÁ¿¿ÉÒÔÓÃÀ´´æ´¢ÔÚÊý¾Ý¿â±íÖеÄÊý¾Ý¡£ÔÚÕâÖÖÇé¿öÏ£¬±äÁ¿Ó¦¸ÃÓµÓÐÓë±íÁÐÏàͬµÄÀàÐÍ¡£ÀýÈ磬students±íµÄfirst_nameÁеÄÀàÐÍΪVARCHAR2(20),ÎÒÃÇ¿ÉÒÔ°´ÕÕÏÂÊö·½Ê½ÉùÃ÷Ò»¸ö±äÁ¿£º
¡¡¡¡DECLARE
¡¡¡¡ v_FirstName VARCHAR2(20);
¡¡
¡¡µ«ÊÇÈç¹ûfirst_nameÁе͍Òå¸Ä±äÁ ......

SQL DateTime²éѯÓë¸ñʽ

select * from orders where month(orderdate)= (select month(orderdate) from orders where orderid=10248)
1.Ò»¸öÔµÚÒ»ÌìµÄ
Select DATEADD(mm, DATEDIFF(mm,0,getdate()), 0)
2.±¾ÖܵÄÐÇÆÚÒ»
Select DATEADD(wk, DATEDIFF(wk,0,getdate()), 0)
3.Ò»ÄêµÄµÚÒ»Ìì
Select DATEADD(yy, DATEDIFF(yy,0,getdate()), 0) ......

SQL´æ´¢¹ý³ÌÈëÃÅ

SQL´æ´¢¹ý³ÌÈëÃÅ
 
Ò»¡¢SQL´æ´¢¹ý³ÌµÄ¸ÅÄÓŵ㼰Óï·¨
¡¡¡¡ÕûÀíÔÚѧϰ³ÌÐò¹ý³Ì֮ǰ£¬ÏÈÁ˽âÏÂʲôÊÇ´æ´¢¹ý³Ì?ΪʲôҪÓô洢¹ý³Ì£¬ËûÓÐÄÇЩÓŵã
¡¡¡¡¶¨Ò壺½«³£ÓõĻòºÜ¸´ÔӵŤ×÷£¬Ô¤ÏÈÓÃSQLÓï¾äдºÃ²¢ÓÃÒ»¸öÖ¸¶¨µÄÃû³Æ´æ´¢ÆðÀ´, ÄÇôÒÔºóÒª½ÐÊý¾Ý¿âÌṩÓëÒѶ¨ÒåºÃµÄ´æ´¢¹ý³ÌµÄ¹¦ÄÜÏàͬµÄ·þÎñʱ,Ö»Ðèµ÷ÓÃexecute ......

SQL LIKE ͨÅä·ûËæ±Ê £¨SqlServer£©

ͨÅä·û ˵Ã÷
_    ÓëÈÎÒâµ¥×Ö·ûÆ¥Åä
 
%    Óë°üº¬Ò»¸ö»ò¶à¸ö×Ö·ûµÄ×Ö·û´®Æ¥Åä
 
[ ]  ÓëÌØ¶¨·¶Î§£¨ÀýÈ磬[a-f]£©»òÌØ¶¨¼¯£¨ÀýÈ磬[abcdef]£©ÖеÄÈÎÒâµ¥×Ö·ûÆ¥Åä¡£
 
[^]  ÓëÌØ¶¨·¶Î§£¨ÀýÈ磬[^a-f]£©»òÌØ¶¨¼¯£¨ÀýÈ磬[^abcdef]£©Ö®ÍâµÄÈÎÒâµ¥×Ö·ûÆ¥Åä¡£
......

OracleÔÚwindowsϰ²×°¼ÍÒª


°²×°£º
ÔËÐÐG:\install\setup.exe°²×°Oracle£¬µ«²»´´½¨Æô¶¯Êý¾Ý¿â
´´½¨Êý¾Ý¿â(ʹÓÃConfiguration And Migration Tools->DataBase Configuration Assistant)
´´½¨¼àÌý³ÌÐò(ʹÓÃConfiguration And Migration Tools->NetManager»òÕß Configuration And Migration Tools->Net Configuration Assistant)
´´½¨·þÎñ ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ