How to Send DateTime Or DbNull to DB using c#?

Question

Hi all.

I have a web form (.aspx) that has a textbox. My user can enter a value into the textbox as a persian date. what should I do is converting texbox.text into DateTime. But sometimes,the textbox has no text within it and so I should take care of it and return null.

when I return null how can I insert null (c#) into DB?

Answer 1

It all depend on how you are doing your data access.. by hand?

If so; there are two common ways of passing a null DateTime around; the original was to use DateTime.MinValue to mean null; the second is to use Nullable<DateTime> (aka DateTime?) to pass the date around. Then in your DAL you detect this and switch to DBNull.Value:

if(someDate == DateTime.MinValue) { // or "== null" for Nullable<DateTime>
    dateParam.Value = DBNull.Value;
} else {
    dateParm.Value = someDate;
}

With LINQ-to-SQL, the Nullable<DateTime> approach should "just work".