Ò׽ؽØͼÈí¼þ¡¢µ¥Îļþ¡¢Ãâ°²×°¡¢´¿ÂÌÉ«¡¢½ö160KB

SQLÖÐdeclareÉêÃ÷±äÁ¿

ÔÚsqlÓï¾äÖÐÌí¼Ó±äÁ¿¡£
declare @local_variable data_type
ÉùÃ÷ʱÐèÒªÖ¸¶¨±äÁ¿µÄÀàÐÍ£¬
¿ÉÒÔʹÓÃsetºÍselect¶Ô±äÁ¿½øÐи³Öµ£¬
ÔÚsqlÓï¾äÖоͿÉÒÔʹÓÃ@local_variableÀ´µ÷ÓñäÁ¿
ÉùÃ÷ÖпÉÒÔÌṩֵ£¬·ñÔòÉùÃ÷Ö®ºóËùÓбäÁ¿½«³õʼ»¯ÎªNULL¡£
ÀýÈ磺declare @id int
         declare @id int = 3
         set @id=2
         select id
         select @id = column_id from table where column_user = 'ABC'


Ïà¹ØÎĵµ£º

oracle sql*plus set &spool½éÉÜ(¶þ)

Oracle spool Ó÷¨Ð¡½á[°ëת°ë¼Ó]
¹ØÓÚSPOOL(SPOOLÊÇSQLPLUSµÄÃüÁ²»ÊÇSQLÓï·¨ÀïÃæµÄ¶«Î÷¡£)
¶ÔÓÚSPOOLÊý¾ÝµÄSQL£¬×îºÃÒª×Ô¼º¶¨Òå¸ñʽ£¬ÒÔ·½±ã³ÌÐòÖ±½Óµ¼Èë,SQLÓï¾äÈ磺
select empno||','||ename||','||sal from emp;
spool³£ÓõÄÉèÖÃ
set colsep' ';¡¡¡¡¡¡ //ÓòÊä³ö·Ö¸ô·û
set echo off;¡¡¡¡¡¡¡¡//ÏÔʾstartÆô¶¯µ ......

Ò»¸öÏîÄ¿Éæ¼°µ½µÄ50¸öSQLÓï¾ä

 /* 
 ±êÌ⣺һ¸öÏîÄ¿Éæ¼°µ½µÄ50¸öSQLÓï¾ä(ÕûÀí°æ) 
 ×÷Õߣº°®Ð¾õÂÞ.ع»ª
 Ê±¼ä£º2010-05-10 
 ËµÃ÷£ºÒÔÏÂÎåÊ®¸öÓï¾ä¶¼°´ÕÕ²âÊÔÊý¾Ý½øÐйý²âÊÔ£¬×îºÃÿ´ÎÖ»µ¥¶ÀÔËÐÐÒ»¸öÓï¾ä¡£ 
 ÎÊÌâ¼°ÃèÊö£º 
 --1.ѧÉú±í 
 Student(S#,Sname,Sage,Ssex) ......

ÅäÖÃSQL Server2005 expressÓëjdbcÁ¬½Ó

ÉÏ΢ÈíÍøÕ¾ÏÂÔØsqlserver2005 jdbc driver °ü
  
  1¡¢½«microsoft sql server 2005 jdbc driver\sqljdbc_1.2\chs\sqljdbc.jar°ü copyµ½·¢²¼ÏµÍ³ µÄ web-inf\libĿ¼ÖÐ
  2¡¢½«microsoft sql server 2005 jdbc driver\sqljdbc_1.2\chs\auth\x86\sqljdbc_auth.dll Îļþcopyµ½ windows ......

mysql sql °ÙÍò¼¶Êý¾Ý¿âÓÅ»¯·½°¸

1.¶Ô²éѯ½øÐÐÓÅ»¯£¬Ó¦¾¡Á¿±ÜÃâÈ«±íɨÃ裬Ê×ÏÈÓ¦¿¼ÂÇÔÚ where ¼° order by Éæ¼°µÄÁÐÉϽ¨Á¢Ë÷Òý¡£
2.Ó¦¾¡Á¿±ÜÃâÔÚ where ×Ó¾äÖжÔ×ֶνøÐÐ null ÖµÅжϣ¬·ñÔò½«µ¼ÖÂÒýÇæ
·ÅÆúʹÓÃË÷Òý¶ø½øÐÐÈ«±íɨÃ裬È磺
select id from t where num is null
¿ÉÒÔÔÚnumÉÏÉèÖÃ
ĬÈÏÖµ0£¬È·±£±íÖÐnumÁÐûÓÐnullÖµ£¬È»ºóÕâ
Ñù²éѯ£º
sel ......

sql ³£Óú¯Êý

SQL³£ÓÃ×Ö·û´®º¯Êý
Ò»¡¢×Ö·ûת»»º¯Êý
1¡¢ASCII()
·µ»Ø×Ö·û±í´ïʽ×î×ó¶Ë×Ö·ûµÄASCII ÂëÖµ¡£ÔÚASCII£¨£©º¯ÊýÖУ¬´¿Êý×ÖµÄ×Ö·û´®¿É²»ÓÑ’À¨ÆðÀ´£¬µ«º¬ÆäËü×Ö·ûµÄ×Ö·û´®±ØÐëÓÑ’À¨ÆðÀ´Ê¹Ó㬷ñÔò»á³ö´í¡£
2¡¢CHAR()
½«ASCII Âëת»»Îª×Ö·û¡£Èç¹ûûÓÐÊäÈë0 ~ 255 Ö®¼ä ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØͼ | ¸ÓICP±¸09004571ºÅ