System.DBNull exception when passing null value

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Here is my code, i was trying to pass null value if the string is empty.

But it throws exception.any one help me what am missing here ?

DateTime strDateTime = System.Convert.ToDateTime(item.TerminationDate);
string conv=System.Convert.ToString (strDateTime);
DateTime dateToSave;
dateToSave = DateTime.Parse(conv);

 if (!String.IsNullOrEmpty(conv))
     dateToSave = DateTime.Parse(conv);
else
    dateToSave= System.DBNull.Value

[edit]Code block added - OriginalGriff[/edit]

Posted 13-Mar-11 21:47pm

shan1395

Updated 13-Mar-11 21:51pm

OriginalGriff

v2

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3 solutions

Solution 2

I'm not that surprised, really.
1) You convert from a string to a DateTime:

C#

DateTime strDateTime = System.Convert.ToDateTime(item.TerminationDate);

2) You convert the DateTime back to a string:

C#

string conv=System.Convert.ToString (strDateTime);

3) You convert the string back to a DateTime:

C#

dateToSave = DateTime.Parse(conv);

4) You then test if the string you just used would have thrown an exception:

C#

if (!String.IsNullOrEmpty(conv))

5) This won't compile:

C#

dateToSave = System.DBNull.Value

Perhaps you need to think this a bit, as there are a number of problems here:

1) It could fail if the item.TerminationDate is not a valid date
2) You don't need to keep transfering between strings and DateTime.
3) You should check before you use, rather than after.
4) You can only assign DateTime values to a DateTime.

What are you actually trying to do?

Posted 13-Mar-11 21:59pm

OriginalGriff

Solution 1

DateTime data types don't support DBNull values. You need to change your dateToSave to an Object, or create a Boolean flag to say if it's populated or not

Posted 13-Mar-11 21:59pm

MarqW

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coommark · Accepted Answer · 2011-03-14T11:59:00

I'd do this if I were you:

string strDateTime = item.TerminationDate.ToString();
DateTime dateToSave;
if (!string.IsNullOrEmpty(strDateTime))
{
    dateToSave = Convert.ToDateTime(strDateTime)
}

That way I wouldn't have to worry about assigning a null value to the DateTime variable. You should include the else { } construct to add code that will execute if the string variable is null.