How to set DateTime variable to Null in C#?

[Reza Solouki]

Hello,

I have a system where it gets its data from a file that is provided
periodically. There are cases where many values such as dates are blank.

Considering DateTime variable doesn't accept null, and SQL Server doesn't
accept DateTime.MinVal ue...

What is the solution to deal with these kind of cases? I probably could
create some work around to send some awkword value that SQL accept and then
treat it from there, but to me there should be some other practical solution
for this!??
(btw: my company hasn't updated to 2.0 yet)

Thanks for your response in advance,
Reza

[Teemu Keiski]

Hi,

DateTime is a value type, it cannot represent null (or DBNull)

simple way is just to set it to DateTime.MinVal ue and when setting values
for stored proc parameters, check for DateTime.MinVal ue, and when that's the
value send null to the database (set DBNull.Value to be param value)

--
Teemu Keiski
ASP.NET MVP, AspInsider
Finland, EU
http://blogs.aspadvice.com/joteke

"Reza Solouki" <Re*********@di scussions.micro soft.com> wrote in message
news:FB******** *************** ***********@mic rosoft.com...

Hello,

I have a system where it gets its data from a file that is provided
periodically. There are cases where many values such as dates are blank.

Considering DateTime variable doesn't accept null, and SQL Server doesn't
accept DateTime.MinVal ue...

What is the solution to deal with these kind of cases? I probably could
create some work around to send some awkword value that SQL accept and
then
treat it from there, but to me there should be some other practical
solution
for this!??
(btw: my company hasn't updated to 2.0 yet)

Thanks for your response in advance,
Reza

[Eliyahu Goldin]

Reza,

Just replace nulls with something suitable for your code when you read, and
do the opposite when you write. That's what I am doing and I don't think
there is anything more elegant.

Eliyahu

"Reza Solouki" <Re*********@di scussions.micro soft.com> wrote in message
news:FB******** *************** ***********@mic rosoft.com...

Hello,

I have a system where it gets its data from a file that is provided
periodically. There are cases where many values such as dates are blank.

Considering DateTime variable doesn't accept null, and SQL Server doesn't
accept DateTime.MinVal ue...

What is the solution to deal with these kind of cases? I probably could
create some work around to send some awkword value that SQL accept and
then
treat it from there, but to me there should be some other practical
solution
for this!??
(btw: my company hasn't updated to 2.0 yet)

Thanks for your response in advance,
Reza

[Mark Rae]

"Reza Solouki" <Re*********@di scussions.micro soft.com> wrote in message
news:FB******** *************** ***********@mic rosoft.com...

Prior to v2, I used to use a separate class for this. Basically, it
simulated the nullable datatype functionality built into v2. I.e. instead of
declaring a DateTime variable / object / class (whatever you want to call
it), I'd declare a NullableDateTim e variable, which has a Value property, a
HasValue property etc.

I can let you have a copy of it if you like...

(btw: my company hasn't updated to 2.0 yet)

As soon as you upgrade, you'll be able to do this:

DateTime? dtmTest = null;

if (dtmTest.HasVal ue)
{
// write the value into the database
}
else
{
// write a NULL into the database
}