处理null和datetime [英] dealing with null and datetime
问题描述
有没有什么好方法可以处理null日期时间。例如，我似乎找不到任何会在日期时间
参数中将空值传递给另一个方法的东西。例如，Convert.dbnull不起作用。
在C＃和SQL Server之间来回获取空值总是
有问题。
-
问候，
Gary Blakely
" GaryDean" < Ga ****** @ newsgroups.nospamwrote in message
news：u7 ************** @ TK2MSFTNGP05.phx.gbl ...
有没有什么好方法可以处理null日期时间。例如，
我似乎找不到任何会在日期时间
参数中将null值传递给另一个方法的东西。例如，Convert.dbnull不起作用。
在C＃和SQL Server之间来回获取空值总是有问题。
使用可以为空的DateTime变量，例如
DateTime？ dtmNullable = null;
问题是DateTime是一个值类型。值类型不能为空。
我通常将2000年1月1日（或任何其他日期）设置为空日期并检查
，就好像你要检查一样null。
George。
" GaryDean" < Ga ****** @ newsgroups.nospamwrote in message
news：u7 ************** @ TK2MSFTNGP05.phx.gbl ...
有没有什么好方法可以处理null日期时间。例如，
我似乎找不到任何会在日期时间
参数中将null值传递给另一个方法的东西。例如，Convert.dbnull不起作用。
在C＃和SQL Server之间来回获取空值总是
有问题。
-
问候，
Gary Blakely
对不起，我不明白。
什么是可空的DateTime变量？
什么是DateTime？ dtmNullable = null;" ;?
您能否在代码中使用它？
谢谢
乔治。
" Mark Rae" < ma ** @ markNOSPAMrae.com写信息
新闻：ON ************** @ TK2MSFTNGP02.phx.gbl ...
< blockquote class =post_quotes>
" GaryDean" < Ga ****** @ newsgroups.nospamwrote in message
news：u7 ************** @ TK2MSFTNGP05.phx.gbl ...
>有没有什么好方法可以处理null日期时间。对于
实例，我似乎找不到任何会将
datetime参数中的null值传递给另一个方法的东西。 Convert.dbnull不适用于
实例。在C＃和SQL Server之间来回获取空值总是有问题的。
使用可以为空的DateTime变量，例如
DateTime？ dtmNullable = null;
Is there any good way in which to deal with null datetimes. For instance, I
can''t seem to find anything that will pass a null value in a datetime
parameter to another method. Convert.dbnull will not work for instance.
Getting nulls back and forth between C# and SQL Server is always
problematic.
--
Regards,
Gary Blakely
"GaryDean" <Ga******@newsgroups.nospamwrote in message
news:u7**************@TK2MSFTNGP05.phx.gbl...
Is there any good way in which to deal with null datetimes. For instance,
I can''t seem to find anything that will pass a null value in a datetime
parameter to another method. Convert.dbnull will not work for instance.
Getting nulls back and forth between C# and SQL Server is always
problematic.Use a nullable DateTime variable e.g.
DateTime? dtmNullable = null;
The problem is that DateTime is a value type. Value type can not be null.
I usually set January 1, 2000 (or any other date) as a null date and check
for it as if you would check for null.
George.
"GaryDean" <Ga******@newsgroups.nospamwrote in message
news:u7**************@TK2MSFTNGP05.phx.gbl...Is there any good way in which to deal with null datetimes. For instance,
I can''t seem to find anything that will pass a null value in a datetime
parameter to another method. Convert.dbnull will not work for instance.
Getting nulls back and forth between C# and SQL Server is always
problematic.
--
Regards,
Gary Blakely
Sorry, I did not understand.
What is "nullable DateTime variable"?
And what is "DateTime? dtmNullable = null;"?
Can you please use it in a code maybe?
Thanks
George.
"Mark Rae" <ma**@markNOSPAMrae.comwrote in message
news:ON**************@TK2MSFTNGP02.phx.gbl..."GaryDean" <Ga******@newsgroups.nospamwrote in message
news:u7**************@TK2MSFTNGP05.phx.gbl...
>Is there any good way in which to deal with null datetimes. For
instance, I can''t seem to find anything that will pass a null value in a
datetime parameter to another method. Convert.dbnull will not work for
instance. Getting nulls back and forth between C# and SQL Server is
always problematic.
Use a nullable DateTime variable e.g.
DateTime? dtmNullable = null;
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