What will be the output of the following?
Create Table MyTable
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values Select * from MyTable
请您将结果贴在回复中。7日后结贴!
Create Table MyTable
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values Select * from MyTable
请您将结果贴在回复中。7日后结贴!
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- [向ALL提问]每日一个小问题 2
- 求一条联表查询SQL语句
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values Select * from MyTablemainkey
-1
0
1
sf
-----------
-1
0
1(3 行受影响)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Microsoft SQL Server 2005 - 9.00.1399.06 (Intel X86)
Oct 14 2005 00:33:37
Copyright (c) 1988-2005 Microsoft Corporation
Enterprise Edition on Windows NT 5.2 (Build 3790: Service Pack 2)
IF OBJECT_ID('aa', 'P') IS NOT NULL
Drop PROCEDURE aa
GO
create proc aa(
@WHCd varchar(20)=''
)
as
set nocount on
if isnull(@WHCd,'')='' set @WHCd='%'select a.MatKey,a.MrNo,sum(a.Qty) as TakQty,max(b.TxnDate) as TakDate
from TxNi_StkDnDetJob a (nolock)
left join TxNi_StkDnHd b (nolock) on a.TxnNo=b.TxnNo
where b.FrWHCd like @WHCd
group by a.MatKey,a.MrNo
return
goexec aa ''
go
如果我将“where b.FrWHCd like @WHCd”注释掉,1s就执行出结果624行;
如果不注释掉,15s才执行出结果;
把“if isnull(@WHCd,'')='' set @WHCd='%'”注释掉,条件换成where (@WHCd='' or b.FrWHCd=@WHCd)也要15s;我要实现的就是当参数为‘’时查所有的,当不为‘’时按参数查询,最好是模糊查询。请问出现以上时间差别的原因,及解决方法。
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values Select * from MyTable
-1
0
1Microsoft SQL Server 2008 (RTM) - 10.0.1600.22 (Intel X86) Jul 9 2008 14:43:34 Copyright (c) 1988-2008 Microsoft Corporation Standard Edition on Windows NT 5.2 <X86> (Build 3790: Service Pack 2) ZL什么意思
mainkey
-----------
-1
0
1(3 行受影响)
Microsoft SQL Server 2005 - 9.00.1399.06 (Intel X86)
Oct 14 2005 00:33:37
Copyright (c) 1988-2005 Microsoft Corporation
Express Edition on Windows NT 5.1 (Build 2600: Service Pack 3)
(1 行受影响)
mainkey
-----------
-1
0
1(所影响的行数为 3 行)
你把条件换成Where b.FrWHCd=@WHCd 看一下时间是多少?
identity函数的用法?
identity属性?
LZ讲讲......
-- Author : htl258(Tony)
-- Date : 2010-06-29 08:09:42
-- Version: Microsoft SQL Server 2008 (RTM) - 10.0.1600.22 (Intel X86)
-- Jul 9 2008 14:43:34
-- Copyright (c) 1988-2008 Microsoft Corporation
-- Developer Edition on Windows NT 5.1 <X86> (Build 2600: Service Pack 2)
-- Blog : http://blog.csdn.net/htl258
----------------------------------------------------------------------------------
IF OBJECT_ID('MyTable')>0
DROP TABLE MyTable
GO
Create Table MyTable
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values Select * from MyTable
/*
mainkey
-----------
-1
0
1(3 行受影响)
*/
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values Select * from MyTablemainkey
-----------
-1
0
1(3 行受影响)
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values Select * from MyTable
mainkey
-----------
-1
0
1
2
3
4(6 行受影响)
/*mainkey
-----------
-1
0
1(3 行受影响)
*/
-----------
-1
0
1(3 行受影响)
mainkey
-1
0
1
Create Table MyTable
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values Select * from MyTablemainkey
-----------
-1
0
1(3 行受影响)
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values Select * from MyTable--结果
mainkey
---------------------
-1
0
1
2
3
-----------
-1
0
1(3 行受影响)
-1
0
1
(1 行受影响)(1 行受影响)(1 行受影响)
mainkey
-----------
-1
0
1(3 行受影响)
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values Select * from MyTable
-1
0
1
(1 個資料列受到影響)(1 個資料列受到影響)(1 個資料列受到影響)
mainkey
-----------
-1
0
1(3 個資料列受到影響)有分拿?
(1 行受影响)(1 行受影响)(1 行受影响)(3 行受影响)
-1
0
1
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values 如果多插入几条值的话,结果如下:
mainkey
-1
0
1
2
3
4
5
2008mainkey
-1
0
1
--结果:
--大家的结果:
问题地址:
http://www.sqlservercentral.com/NewsletterArchive/2010/06/29/5337441
这个结果明显地不正确,难道老外们用的SQL和我们用的SQL有什么不同?又或者SQL2008和SQL2000不同?
Create Table MyTable
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values Select * from MyTable--结果
mainkey
-----------------------
-1
0
1
不用思考了,75楼应该是编辑错误,或者作者输错:mainkey int not null identity (-1,1)
mainkey int not null identity (-1,-1) 这个才能套他的正确结果
--建表
Create Table MyTable
(
mainkey int not null identity (-1,1)
)
GO
insert into MyTable default values
insert into MyTable default values
insert into MyTable default values
--查询
Select * from MyTable
--结果
-1
0
1