sql 2005 rownumÓ÷¨ÒÔ¼°´øorder by ×Ó²éѯµÄÓ÷¨
-- sql 2005
1.rownumÓ÷¨
select * from(
Select rownum=row_number() over(order by 1),* from table
)a where rownum between 1 and 10
2.´øorder by ×Ó²éѯµÄÓ÷¨
sleect * from(select TOP 100 percent * from table order id ) a
Ïà¹ØÎĵµ£º
USE MASTER
GO
--´´½¨Êý¾Ý¿âÎļþ´æ·ÅĿ¼
EXEC XP_CMDSHELL 'MKDIR D:\LOANSTUMIS'
IF EXISTS(SELECT *
from SYSDATABASES
WHERE NAME = 'LOANSTU')
DROP DATABASE LOANSTU
GO
--´´½¨Êý¾Ý¿â
CREATE DATABASE LOANSTU
ON
(
NAME = 'LOANSTU_DATA',
FILENAME = 'D:\LOANSTUMIS\LOANSTU_DATA.MDF',
......
½ñÌìÔÚÅäÖÃÊý¾Ý¿â·¢²¼ºÍ·Ö·¢Ê±×ÜÊDZ¨³öÏÖ 18483 ´íÎó
Ìáʾ˵£º´íÎó 18483:δÄÜÁ¬½Óµ½·þÎñÆ÷ "XXX"£¬ÒòΪ 'distributor_admin'δÔڸ÷þÎñÆ÷É϶¨ÒåΪԶ³ÌµÇ½¡£
Îҵķ¢²¼ºÍ·Ö·¢ÊÇͬһ¸ö·þÎñÆ÷£¬"XXX" ΪÎҵĻúÆ÷Ãû£¬·Ö·¢Êý¾Ý¿âÊÇĬÈϵÄÃû³Æ£¬¶øÎÒÔÚÁíÍâһ̨»úÆ÷ÉÏ×öʱ¾ÍÕý³£¡£
1¡¢ÉèÖù²Ïí¸´ÖÆÄ¿Â¼:
......
¸øÄã¸ö×îÏêϸµÄ°É ¿ÉÄÜÓÐÄãÒªµÄÄÚÈÝ
ËøµÄ¸ÅÊö
Ò». ΪʲôҪÒýÈëËø
¶à¸öÓû§Í¬Ê±¶ÔÊý¾Ý¿âµÄ²¢·¢²Ù×÷ʱ»á´øÀ´ÒÔÏÂÊý¾Ý²»Ò»ÖµÄÎÊÌâ:
¶ªÊ§¸üÐÂ
A,BÁ½¸öÓû§¶ÁͬһÊý¾Ý²¢½øÐÐÐÞ¸Ä,ÆäÖÐÒ»¸öÓû§µÄÐ޸Ľá¹ûÆÆ»µÁËÁíÒ»¸öÐ޸ĵĽá¹û,±ÈÈ綩Ʊϵͳ
Ôà¶Á
AÓû§ÐÞ¸ÄÁËÊý¾Ý,ËæºóBÓû§ÓÖ¶Á³ö¸ÃÊý¾Ý,µ«AÓû§ÒòΪijЩÔÒòÈ¡Ï ......
½ñÌì×öSQL ÓÅ»¯£¬²éÕÒÖ´Ðмƻ®Ê±£¬Ö´Ðмƻ®£¬·¢ÏÖ´ËÖ´Ðмƻ®ÓëÒÔÍùµÄ¼Æ»®ÓÐËùÇø±ð£»ÕÒ¼»¥ÁªÍø£¬ÖÕÓÚÕÒһƪÓйØÑо¿±È½ÏÉîÈëµÄÎÄÕ£»
ÔÖ´Ðмƻ®Ê¹ÓõÄÊÇË÷ÒýɨÃ裬ͻȻһÏ»áʹÓÃË÷Òý¸²¸Ç¼¼Êõ£¬Ð§ÂÊ´óÔö£»
SELECT * µÄÕæÏࣺË÷Òý¸²¸Ç(index coverage)
SELECT *µÄЧÂʺÜÔã¸âÂ𣿵±È»£¬ËùÓÐÈ˶¼ÖªµÀÕâÒ»µã£¬µ«ÊÇΪʲô ......
´óÐÍϵͳµÄÉú²ú»·¾³£¬Ò»°ãÇé¿öÏ£¬ÎÒÃÇÆÀ¼ÛÒ»Ìõ²éѯÊÇ·ñÓÐЧÂÊ£¬¸ü¶àµÄÊǹØ×¢Âß¼ IO( ÖÁÓÚΪʲô£¬»ØÍ·²¹Ò»Æª ) ¡£ÎÒÃdz£Ëµ£¬“Òª½¨±ëº·µÄË÷Òý”¡¢“Ҫд¸ßЧµÄ SQL ”£¬Æäʵ×îÖÕÄ¿µÄ¾ÍÊÇÔÚÏàͬ½á¹û¼¯Çé¿öÏ£¬¾¡¿ÉÄܼõÉÙÂß¼ IO ¡£
1.1 where Ìõ¼þµÄÁÐÉ϶¼µÃÓÐͳ¼ÆÐÅ ......