SQLÖÐCONVERTת»¯º¯ÊýµÄÓ÷¨
Õª×Ô£ºhttp://www.cnblogs.com/dicky/archive/2007/01/12/618453.html
¸ñʽ:
CONVERT(data_type,expression[,style])
˵Ã÷:
´ËÑùʽһ°ãÔÚʱ¼äÀàÐÍ(datetime,smalldatetime)Óë×Ö·û´®ÀàÐÍ(nchar,nvarchar,char,varchar)
Ï໥ת»»µÄʱºò²ÅÓõ½.
Àý×Ó:
SELECT CONVERT(varchar(30),getdate(),101) now
½á¹ûΪ:
now
---------------------------------------
|09/15/2001
===================================================================
styleÊý×ÖÔÚת»»Ê±¼äʱµÄº¬ÒåÈçÏÂ:
------------------------------------------------------------------------------------------------------------
Style(2λ±íʾÄê·Ý) | Style(4λ±íʾÄê·Ý) | ÊäÈëÊä³ö¸ñʽ
------------------------------------------------------------------------------------------------------------
0 | 100 | mon dd yyyy hh:miAM(»òPM)
------------------------------------------------------------------------------------------------------------
1 | 101 ÃÀ¹ú | mm/dd/yy &
Ïà¹ØÎĵµ£º
ºÜ¶àÈËÌØ±ðϲ»¶ÓÃÊÓͼ,µ«ÓеÄÈË´ÓÀ´²»ÓÃÊÓͼ.Õâ¶¼ÊÇÁ½ÖÖ²»Á¼µÄϰ¹ß. ÒªÃ÷È·ÊÓͼ¿ÉÒÔÍê³ÉµÄ¹¤×÷ÒÔ¼°Ê¹Óó¡ºÏ.
1.×èֹѡÔñ±£ÃÜÁÐ
2.½µµÍÓû§¶ÁÈ¡Êý¾Ý¿âÄÚÊý¾ÝµÄ¸´ÔÓÐÔ
3.ÔÚÊý¾Ý¿âÖÐÌí¼ÓË÷ÒýÒÔ¼ÓËÙ ......
mysql : ½«Ò»¸ö±íµÄÊý¾Ý²åÈëµ½newT ÖÐ
£¨newT ±íÐë´æÔÚ£¬ÇҽṹÓëselect Óï¾ä¶ÔÓ¦µÄ½á¹¹Í¬ £¬×îºÃ²»ÓÃ* ¶øÊǾßÌå×ֶΣ©
insert into newT select * from t1 where ...
Ò²¿ÉÒÔcreate table newT select f1,f2 from t1; (select into µÄÌæ´ú·½·¨£¬my ......
ÈçºÎ´ÓEXPDPµ¼³öµÄÎļþÀï»ñµÃÓû§ÊÚȨµÄSQLÓï¾ä
´òËãÇ¨ÒÆÒ»ÏµÍ³£¬ÓÉÓÚÊÇ¿çÆ½Ì¨µÄÇ¨ÒÆ£¬RMANÊDz»ÄÜÓÃÁË£¬¿¼ÂÇʹÓÃEXPDP/IMPDPÀ´½øÐе¼Èëµ¼³ö£¬µ¼Èë¹ý³Ì·¢ÏÖN¶àÓû§µÄȨÏÞ¸ã³öÁË£¬Âé·³ÖØµ¼ÊÇ¿ÉÒÔ»¨Ê±¼äÌ«³¤£¬Ñо¿ÁËһϣ¬Éú³ÉÁËÈ«²¿µÄSQLµÄ½Å±¾¡£
impdp system/manager schemas=user DIRECTORY=DUMP_FILES ......
Èç¹ûÄãÕýÔÚ¸ºÔðÒ»¸ö»ùÓÚSQL ServerµÄÏîÄ¿£¬»òÕßÄã¸Õ¸Õ½Ó´¥SQL Server£¬Äã¶¼ÓпÉÄÜÒªÃæÁÙһЩÊý¾Ý¿âÐÔÄܵÄÎÊÌ⣬ÕâÆªÎÄÕ»áΪÄãÌṩһЩÓÐÓõÄÖ¸µ¼£¨ÆäÖдó¶àÊýÒ²¿ÉÒÔÓÃÓÚÆäËüµÄDBMS£©¡£
ÔÚÕâÀÎÒ²»´òËã½éÉÜʹÓÃSQL ServerµÄÇÏÃÅ£¬Ò²²»ÄÜÌṩһ¸ö°üÖΰٲ¡µÄ·½°¸£¬ÎÒËù×öµÄÊÇ×ܽáһЩ¾Ñé----¹ØÓÚÈçºÎÐγÉÒ»¸öºÃµÄÉè¼Æ¡£Õ ......
Student(S#,Sname,Sage,Ssex) ѧÉú±í
Course(C#,Cname,T#) ¿Î³Ì±í
SC(S#,C#,score) ³É¼¨±í
Teacher(T#,Tname) ½Ìʦ±í
ÎÊÌ⣺
1¡¢²éѯ“001”¿Î³Ì±È“002”¿Î³Ì³É¼¨¸ßµÄËùÓÐѧÉúµÄѧºÅ£»
select a.S# from (select s#,score from SC where C#='001') a,(select s#,score
fr ......