Visual Basic 2005 Express:
SQL won't permit null dates in a table. I would like to test for this condition and replace the null date with a DefaultDate (01/01/1901). How do I test for a null date in an SQL table The following code gives an error saying that DBNull is a type and cannot be used in an expression.
If
PatientBindingSource.Current("BirthDate") = DBNull ThenPatientBindingSource.Current("BirthDate")=DefaultDate
End If
How do I test for null date in SQL table?
DanielMac
Yes, I entered a default value in the properties window for BirthDate.
I also have the following statement in the Public area of the program:
Dim DefaultDate as date = "01/01/1901"
HG71
The isdbnull method in VB.Net seems to do the trick.
If Isdbnull(PatientBindingSource.Current("BirthDate") ) Then
PatientBindingSource.Current("BirthDate") =DefaultDate
end if
Or, You can use a statement such as
If PatientBindingSource.Current("BirthDate") Is DBNull.Value Then
PatientBindingSource.Current("BirthDate") =DefaultDate
end if
kenneth123
Surprisingly, I still get the Null Value error!
Public Sub PatientBindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PatientBindingNavigatorSaveItem.ClickIf IsDBNull(PatientBindingSource.Current("BirthDate")) Then
PatientBindingSource.Current("BirthDate") = DefaultDate
End If
Me.Validate()
Me.PatientBindingSource.EndEdit()
Me.PatientTableAdapter.Update(Me.PatientDataSet.Patient)
End Sub
Jayakumar A
Have you initialised DefaultDate
Ed1112ward
Did you check the field values in the dataset and the database - did you make the default value change after you created the dataset
Changing the database field will not automatically update the dataset and vice versa.
Also if you seeing a value in the field then its probably not a dbnull that you need to test for.
Malic Huang
Do the testing for dbnull methods work if you code step through them. When you get to the line of code and you look at the value of the field is it showing as dbnull
Was this in the dataset and the database.
Gabrielle Erlingen