Handling NULL datetime values

[Venkrishna]

Hi

How would I handle this.

The code is below

DateTime invoicedate = ((DateTime)invoiceReader["inv_date"]);

If the inv_date is returned NULL from the database I get the following error.

System.InvalidCastException: Specified cast is not valid.

Any ideas how to resolve this error?

VK

[jmcilhinney]

If invoiceReader.IsDBNull("inv_date") Then
    'The inv_date column contains a null value.
Else
    Dim invoiceDate As Date = CDate(invoiceReader("inv_date"))
End If

or:

Dim invoiceDate As Nullable(Of Date)
 
If invoiceReader.IsDBNull("inv_date") Then
    invoiceDate = Nothing
Else
    invoiceDate = CDate(invoiceReader("inv_date"))
End If

[kleinma]

Moved to C#

[jmcilhinney]

Now I'll answer in C#:

if (invoiceReader.IsDBNull("inv_date"))
{
    // The inv_date column contains a null value.
}
else
{
    DateTime invoiceDate = invoiceReader["inv_date"];
}

or:

Nullable<DateTime> invoiceDate;

if (invoiceReader.IsDBNull("inv_date"))
{
    invoiceDate = null;
}
else
{
    invoiceDate = invoiceReader["inv_date"];
}