求助：关于使用between日期 and 日期 的效率问题

[kid_1982]

在对一段时间内数据进行选择时，同样使用“between日期 and 日期”，日期为常量时快，使用变量时慢。比如：
select * from salesdetails where InvoiceDate between ‘2007-10-21’and ‘2007-10-22’

要比下面用变量的快很多

declare @date1 as datetime,@date2 as datetime
set @date1 = ‘2007-10-21’
set @date2 = ‘2007-20-22’
select * from salesdetails where InvoiceDate between @date1 and @date2

[ojuju10]

用>=和<=试一下：
select * from salesdetails where InvoiceDate >=@date1 and InvoiceDate <= @date2

[yuanfang2512]

都差不多，不过经常习惯用select * from salesdetails where InvoiceDate between ‘2007-10-21’and ‘2007-10-22’

[fwacky]

select * from salesdetails where InvoiceDate between ‘2007-10-21’and ‘2007-10-22’
这个好一点！

[kid_1982]

据我所知，使用between会比《＝ 》＝的好，但我现在想知道，常量和变量是否会影响速度哦
而且我的SQL还必须使用变量 55555

[Limpire]

在对一段时间内数据进行选择时，同样使用“between日期 and 日期”，日期为常量时快，使用变量时慢。比如：
select * from salesdetails where InvoiceDate between ‘2007-10-21’and ‘2007-10-22’

要比下面用变量的快很多

declare @date1 as datetime,@date2 as datetime
set @date1 = ‘2007-10-21’
set @date2 = ‘2007-20-22’
select * from salesdetails where InvoiceDate between @date1 and @date2

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那就想办法把变量变成常量：

--declare @date1 as datetime,@date2 as datetime
declare @date1 as varchar(10),@date2 as varchar(10)
set @date1='2007-10-21'
set @date2='2007-20-22'
exec ('select * from salesdetails where InvoiceDate between '''+@date1+''' and '''+@date2+'''')