handling DBNULL

[Bill Crawley]

Hi All,

I have a column on an SQL Server DB that is declared as type integer and is nullable.

I have a query that includes this column that is bound to a typed dataset.

This is the Typed Dataset's Property

            <Global.System.Diagnostics.DebuggerNonUserCodeAttribute()> _
            Public Property RateableValue() As Integer
                Get
                    Try
                        Return CType(Me(Me.tableCustomerSystemFieldsAssetLocation.RateableValueColumn), Integer)
                    Catch e As Global.System.InvalidCastException
                        Throw New Global.System.Data.StrongTypingException("The value for column 'RateableValue' in table 'CustomerSystemFieldsAssetLocation'" & _
                                " is DBNull.", e)
                    End Try
                End Get
                Set(ByVal value As Integer)
                    Me(Me.tableCustomerSystemFieldsAssetLocation.RateableValueColumn) = value
                End Set
            End Property

How do I test for a null value against this or should I change the code above. As soon as It hits the row:

Return CType(Me(Me.tableCustomerSystemFieldsAssetLocation.RateableValueColumn), Integer)

My app crashes with conversion error DBnull to integer.

[HairyMonkeyMan]

Is tableCustomerSystemFieldsAssetLocation a row from the datatable? If so, check whether Me.tableCustomerSystemFieldsAssetLocation.IsNull("RateableValueColumn") is true before getting the value.