SQL×¢Èë©¶´È«½Ó´¥ ½ø½×ƪ
µÚÒ»½Ú¡¢SQL×¢ÈëµÄÒ»°ã²½Öè
Ê×ÏÈ£¬Åжϻ·¾³£¬Ñ°ÕÒ×¢Èëµã£¬ÅжÏÊý¾Ý¿âÀàÐÍ£¬ÕâÔÚÈëÃÅÆªÒѾ½²¹ýÁË¡£
Æä´Î£¬¸ù¾Ý×¢Èë²ÎÊýÀàÐÍ£¬ÔÚÄÔº£ÖÐÖØ¹¹SQLÓï¾äµÄÔò£¬°´²ÎÊýÀàÐÍÖ÷Òª·ÖΪÏÂÃæÈýÖÖ£º
(A) ID=49 ÕâÀà×¢ÈëµÄ²ÎÊýÊÇÊý×ÖÐÍ£¬SQLÓï¾äÔò´óÖÂÈçÏ£º
Select * from ±íÃû where
×Ö¶Î=49
×¢ÈëµÄ²ÎÊýΪID=49 And [²éѯÌõ¼þ]£¬¼´ÊÇÉú³ÉÓï¾ä£º
Select * from ±íÃû where ×Ö¶Î=49 And
[²éѯÌõ¼þ]
(B) Class=Á¬Ðø¾ç ÕâÀà×¢ÈëµÄ²ÎÊýÊÇ×Ö·ûÐÍ£¬SQLÓï¾äÔò´óÖ¸ÅÈçÏ£º
Select * from ±íÃû
where ×Ö¶Î=’Á¬Ðø¾ç’
×¢ÈëµÄ²ÎÊýΪClass=Á¬Ðø¾ç’ and [²éѯÌõ¼þ] and ‘’=’ £¬¼´ÊÇÉú³ÉÓï¾ä£º
Select *
from ±íÃû where ×Ö¶Î=’Á¬Ðø¾ç’ and [²éѯÌõ¼þ] and ‘’=’’
(C) ËÑË÷ʱû¹ýÂ˲ÎÊýµÄ£¬Èçkeyword=¹Ø¼ü×Ö£¬SQLÓï¾äÔò´óÖÂÈçÏ£º
Select * from ±íÃû
where ×Ö¶Îlike ’%¹Ø¼ü×Ö%’
×¢ÈëµÄ²ÎÊýΪkeyword=’ and [²éѯÌõ¼þ] and ‘%25’=’£¬
¼´ÊÇÉú³ÉÓï¾ä£º
Select * from ±íÃû where×Ö¶Îlike ’%’ and [²éѯÌõ¼þ] and ‘%’=’%’
½Ó×Å£¬½«²éѯÌõ¼þÌæ»»³ÉSQLÓï¾ä£¬²Â½â±íÃû£¬ÀýÈ磺
ID=49 And (Select Count(*) from Admin)>=0
Èç¹ûÒ³Ãæ¾ÍÓëID=49µÄÏàͬ£¬ËµÃ÷¸½¼ÓÌõ¼þ³ÉÁ¢£¬¼´±íAdmin´æÔÚ£¬·´Ö®£¬¼´²»´æÔÚ£¨ÇëÀμÇÕâÖÖ·½·¨£©¡£Èç´ËÑ»·£¬Ö±ÖÁ²Âµ½±íÃûΪֹ¡£
±íÃû²Â³öÀ´ºó£¬½«Count(*)Ìæ»»³ÉCount(×Ö¶ÎÃû)£¬ÓÃͬÑùµÄÔÀí²Â½â×Ö¶ÎÃû¡£
ÓÐÈË»á˵£ºÕâÀïÓÐһЩżȻµÄ³É·Ö£¬Èç¹û±íÃûÆðµÃºÜ¸´ÔÓû¹æÂɵģ¬ÄǸù±¾¾ÍûµÃÍæÏÂÈ¥ÁË¡£ËµµÃºÜ¶Ô£¬ÕâÊÀ½ç¸ù±¾¾Í²»´æÔÚ100%³É¹¦µÄºÚ¿Í¼¼Êõ£¬²ÔÓ¬²»¶£ÎÞ·ìµÄµ°£¬ÎÞÂ۶༼Êõ¶à¸ßÉîµÄºÚ¿Í£¬¶¼ÊÇÒòΪ±ðÈ˵ijÌÐòдµÃ²»ÑÏÃÜ»òʹÓÃÕß±£ÃÜÒâʶ²»¹»£¬²ÅÓеÃÏÂÊÖ¡£
ÓеãÅÜÌâÁË£¬»°Ëµ»ØÀ´£¬¶ÔÓÚSQLServerµÄ¿â£¬»¹ÊÇÓа취ÈóÌÐò¸æËßÎÒÃDZíÃû¼°×Ö¶ÎÃûµÄ£¬ÎÒÃÇÔڸ߼¶ÆªÖлá×ö½éÉÜ¡£
×îºó£¬ÔÚ±íÃûºÍÁÐÃû²Â½â³É¹¦ºó£¬ÔÙʹÓÃSQLÓï¾ä£¬µÃ³ö×ֶεÄÖµ£¬ÏÂÃæ½éÉÜÒ»ÖÖ×î³£Óõķ½·¨£AsciiÖð×Ö½âÂë·¨£¬ËäÈ»ÕâÖÖ·½·¨ËٶȺÜÂý£¬µ«¿Ï¶¨ÊÇ¿ÉÐеķ½·¨¡£
ÎÒÃǾٸöÀý×Ó£¬ÒÑÖª±íAdminÖдæÔÚusername×ֶΣ¬Ê×ÏÈ£¬ÎÒÃÇÈ¡µÚÒ»Ìõ¼Ç¼£¬²âÊÔ³¤¶È£º
http://www.19cn.com/showdetail.asp?id=49 and (select top 1
len(username) from Admin)>0
ÏÈ˵Ã÷ÔÀí£ºÈç¹ûtop
1µÄusername³¤¶È´óÓÚ0£
Ïà¹ØÎĵµ£º
˵Ã÷£º¸öÈ˸оõÔÚJavaÁìÓò´óÐÍ¿ª·¢¶¼Àë²»ÁËORMµÄÉíÓ°£¬ËùνµÄSSH¾ÍÊÇSpring+Struts+Hibernate£¬³ýÁËÔÚѧϰ»ù´¡ÖªÊ¶µÄʱºò±»¸æÖª¿ÉÒÔʹÓÃJDBC²Ù×÷Êý¾Ý¿âÖ®Í⣬´óÁ¿µÄÊé¼®Öж¼Êǽ²ÊöʹÓÃHibernateÕâ¸öORM¹¤¾ßÀ´²Ù×÷Êý¾Ý¡£ÔÚ.NETÖвÙ×÷Êý¾Ý¿âµÄ·½Ê½ÓжàÖÖ£¬³ýÁË×îÖ±½ÓµÄ·½Ê½¾ÍÊÇʹÓÃADO.NETÖ®Í⣬»¹¿ÉÒÔʹÓÃNHiber ......
½ñÌìÁ·Ï°ÔÚJSPÒ³ÃæÖÐʵÏÖ·ÖҳЧ¹û£¬ÔÚ²éѯÓï¾ä·½ÃæÇ£³¶µ½ÁËtopµÄÓ÷¨¡£¼òÒª×öÒ»ÏÂ×ܽ᣺
ΪʵÏÖÀàËÆtopµÄ¹¦ÄÜ£¬ÎÒÃÇÔÚSQL ServerÖкÍMySQLÖÐʹÓõ½µÄSQLÓï¾äÊDz»Í¬µÄ¡£
1¡¢ÔÚSQL ServerÖУ¬ÎÒÃÇʹÓà select top N * ......
ÈçºÎ´´½¨ SQL Server 2005 ÐÂÕË»§£¿
Ê×ÏÈÒªÉèÖÃSQL Server 2005µÄ·ÃÎÊ·½Ê½
1´ò¿ªSQL Server Management Studio
2·þÎñÆ÷Ãû³ÆÉÏÓÒ¼üÑ¡Ôñ“ÊôÐÔ”£¬´ò¿ª“·þÎñÆ÷ÊôÐÔ”¶Ô»°¿ò£¬ÔÚ“Ñ¡ÔñÒ³”ÀïÑ¡Ôñ“°²È«ÐÔ”£¬ÔÚ“·þÎñÆ÷Éí·ÝÑéÖ¤”ÀïÑ¡Ôñ“SQL ServerºÍWindows É ......
1Ð޸Ļù±¾±í
Ìí¼ÓÁÐ alter table tableName add<ÐÂÁÐÃû><Êý¾ÝÀàÐÍ>[ÍêÕûÐÔÔ¼Êø]
ɾ³ýÁÐ alter table tableName drop<ÐÂÁÐÃû><Êý¾ÝÀàÐÍ>[ÍêÕûÐÔÔ¼Êø]
2´´½¨
½¨±ícreate table tableName(
id primary key AUTO_INCREMENT(mysql);
id primary key identity(1,1)(s ......