SQLµÝ¹é²éѯÊý¾Ý
Tree±íÈçÏÂ:
NodeId ParentId NodeName
0 -1 Ò»
1 0 ¶þ
9 1 Èý
10 9 ËÄ
12 10 Îå
18 1 Áù
ÒÑÖª£ºNodeid Äܵõ½ NodeName µÄµÝ¹éÁ¬½Ó×Ö·û´®Âð£¿
Àý£º ÒÑÖª ½á¹û
NodeId:10 ËÄÈý¶þÒ»
NodeId:18 Áù¶þÒ»
NodeId:1 ¶þÒ»
½â¾ö·½·¨£º
1¡¢´´½¨±í½á¹¹¡£
³ÌÐò´úÂë
create table Tree(NodeId int,Paren
Ïà¹ØÎĵµ£º
±íÖÐÖ÷¼ü±ØÐëΪ±êʶÁУ¬[ID] int IDENTITY (1,1)
1.·ÖÒ³·½°¸Ò»£º(ÀûÓÃNot InºÍSELECT TOP·ÖÒ³)
Óï¾äÐÎʽ£º
SELECT TOP Ò³¼Ç¼ÊýÁ¿ *
from ±íÃû
WHERE (ID NOT IN
(SELECT TOP (ÿҳÐÐÊý*(Ò³Êý-1)) ID
from ±íÃû
ORDER BY ID))
ORDER BY ID
//×Ô¼º»¹¿ÉÒÔ¼ÓÉÏһЩ²éѯ ......
ÔÚsql Server ´Ó¿ª·¢»·¾³ÍùÉú²ú»·¾³²¿Êðʱ£¬ÒòΪ¿Í»§ÄÇÀïÓõÄÊÇÓ¢Îİ汾£¬ËùÒÔ´´½¨Êý¾Ý¿âÒÔºó£¬ÒªÉèÖÃÒ»ÏÂÊý¾Ý¿âÅÅÐò¹æÔò¡£
µ«ÊÇÔÚ´æ´¢¹ý³ÌÖУ¬ÓеijÌÐòԱʹÓÃÁËÁÙʱ±í£¬ÒòΪÁÙʱ±íÊÇ´æ´¢ÔÚϵͳÊý¾Ý¿âtempdbÖУ¬Èç¹ûϵͳÁÙʱÊý¾Ý¿âûÓнøÐÐÅÅÐò¹æÔòµÄÉèÖ㬳ÌÐò»¹Êdzö´í£¬½â¾ö°ì·¨¾ÍÊÇÉèÖÃÁÙʱÊý¾Ý¿âµÄÅÅÐò¹æÔò»òÕß´´½¨ÁÙÊ ......
CREATE proc page
@RecordCount int output,
@QueryStr nvarchar(100)='table1',--±íÃû¡¢ÊÓͼÃû¡¢²éѯÓï¾ä
@PageSize int=20, --ÿҳµÄ´óС(ÐÐÊý)
@PageCurrent int=2, --ÒªÏÔʾµÄÒ³ ´Ó0¿ªÊ¼
@FdShow nvarchar (1000)='*', --ÒªÏÔʾµÄ×Ö¶ÎÁбí
@IdentityStr nvarchar (100)='id', --Ö÷¼ü
@WhereStr nvarchar ......
´Ó8iµ½10g£¬Oracle²»¶Ï½ø»¯×Ô¼ºµÄSQL TuningÖÇÄÜ£¬Ò»Ð©Ãؼ®¼¶µÄÓÅ»¯¿Ú¾÷ÒѾʧЧ¡£
µ«ÎÒϲ»¶Ê§Ð§£¬²»Óüǿھ÷£¬²Ù¸öToad for Oracle Xpert
£¬°´ÕÕ´ó·½ÏòÊæÊæ·þ·þµÄ
µ÷ÓŲÅÊǰ®×öµÄÊÂÇé¡£
1.Excution Plan
Excution
PlanÊÇ×î»ù±¾µÄµ÷ÓŸÅÄ²»¹ÜÄãµÄµ÷ÓÅ´µµÃÈçºÎÌ ......
×Ö·ûÀàÐÍ£º
CHAR(size)£º¹Ì¶¨³¤¶È×Ö·û´®£¬×î´ó³¤¶È2000 bytes
VARCHAR2(size)£º¿É±ä³¤¶ÈµÄ×Ö·û´®£¬×î´ó³¤¶È4000 bytes£¬¿É×öË÷ÒýµÄ×î´ó³¤¶È749
NCHAR(size)£º¸ù¾Ý×Ö·û¼¯¶ø¶¨µÄ¹Ì¶¨³¤¶È×Ö·û´®£¬×î´ó³¤¶È2000 bytes
NVARCHAR2(size)£º¸ù¾Ý×Ö·û¼¯¶ø¶¨µÄ¿É±ä³¤¶È×Ö·û´®£¬×î´ó³¤¶È4000 byte
LONG£º±ä³¤µÄ×Ö·û´®£¬×î´ó³¤¶ÈÏÞ ......