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/*
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thid other
a 1
a 1
b 0
b 0
b 0
c 2
c 2
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thid other
a 1
a 2
b 0
b 1
b 2
c 2
c 3
*/
if OBJECT_ID('tb') is not null
drop table tb
go
create table tb (id varchar(10) ,value int)
insert tb select
'a' , 1 union all select
'a' , 1 union all select
'b' , 0 union all select
'b' , 0 union all select
'b' , 0 union all select
'c' , 2 union all select
'c' , &nb
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±íÖÐÖ÷¼ü±ØÐëΪ±êʶÁУ¬[ID] int IDENTITY (1,1)
1.·ÖÒ³·½°¸Ò»£º(ÀûÓÃNot InºÍSELECT TOP·ÖÒ³)
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SELECT TOP Ò³¼Ç¼ÊýÁ¿ *
from ±íÃû
WHERE (ID NOT IN
(SELECT TOP (ÿҳÐÐÊý*(Ò³Êý-1)) ID
from ±íÃû
ORDER BY ......
--ÏÔʾ°æ±¾ºÅ£¬µ±Ç°ÈÕÆÚ
SELECT VERSION(),CURRENT_DATE(),NOW();
--Ãâ·ÑµÄ¼ÆËãÆ÷
SELECT (20+5)*4 AS RESULT,SIN(PI()/3);
--´´½¨Êý¾Ý¿â
CREATE DATABASE databasename;
--ɾ³ýÊý¾Ý¿â
DROP DATABASE databasename;
--ÏÔʾµ±Ç°´æÔÚµÄÊý¾Ý¿â
SHOW DATABASES;
--Ñ¡ÔñÊý¾Ý¿â
USE ......
http://www.cnblogs.com/yinzhenzhixin/archive/2009/01/07/1371064.html
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SELECT [Id],[Name],[Comment] from [Product1]
UNION
SELECT [Id],[Name],[Comment] from [Product2]
ÉÏÃæµÄ´úÂë¿ ......
±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¿ÉÒÔ¼ÓÉÏһЩ²éѯÌõ¼þ
Àý:
select top 2 ......
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SqlDataSourceEnumerator SseInstance = SqlDataSourceEnumerator.Instance;
//ServerName:·þÎñÆ÷Ãû;
//InstanceName:ʵÀýÃû;
//IsClustered:ÊÇ·ñΪȺ¼¯·þÎñÆ÷µÄÒ»²¿·Ö;
//Version:°æ±¾,8.*ÊÇSQL 2000,9.*ÊÇSQL 2005
DataTable DtSqlInstance = SseInstance.GetDataSources();
×¢£º ......