Question

这两个功能中的哪一个更有效？ toDate1或toDate2 - 还有更好的东西吗？

use Something
go
-- All SQL versions
create function toDate1(@t datetime)  
    returns datetime as begin  
    declare @return datetime  
    select  @return = dateadd(day,datediff(day,0,@t),0)
    return  @return end
go
-- SQL 2008 ->
create function toDate2(@t datetime)  
    returns datetime as begin  
    declare @return datetime  
    select  @return = convert(date, @t) 
    return  @return end

Answer 1

SELECT convert(date, cast ('2014-01-01 10:11:12' as datetime), 106)

返回日期'2014-01-01' cast ('2014-01-01 10:11:12' as datetime)是日期时间变量。请查看msdn了解更多详情

仅从DateTime获取日期部分（SQL函数）

1 个答案: