Try vbNull, rather than DBNull.Value.
On Fri, Apr 8, 2011 at 9:36 PM, Darron and Kerrie <
dkpritch...@optusnet.com.au> wrote:
> I have just started programming in VB.net.
>
> I am recoding an old VB6.0 program to VB.net, and having a problem with
> setting a database field back to null.
>
> The VB6.0 code was:
>
> Set rs = OpenTable("select * from tblunits where unit = " & "'" & temp &
> "'")
> rs!status = "Available"
> rs!eventnum = Null
> rs.Update
>
> I have tried a number of different way in VB.net but always get errors.
> Here is my current code.
>
>
> Dim
> sqlda As New SqlDataAdapter
>
> Dim SQLcmd As New SqlCommand
>
> Dim TableFlag As DataTable
>
> Dim drunitstatus As DataRow
>
> With SQLcmd
>
> .Connection = conn
>
> .CommandType =
> CommandType.Text
>
> .CommandText = (
> "select * from tblunits where unit = '" & UnitName & "'")
>
> End With
>
> sqlda =
> New SqlDataAdapter(SQLcmd)
>
> TableFlag =
> New DataTable
>
> sqlda.Fill(TableFlag)
>
> drunitstatus = TableFlag.Rows(0)
>
> drunitstatus("status") = "Available"
>
> drunitstatus("eventnum") = DBNull.value 'This appear to be the problem
> line "eventnum" is int32 and allow nulls
>
> Dim
> sCB As SqlCommandBuilder = New SqlCommandBuilder(sqlda)
>
> sqlda.Update(TableFlag)
>
>
>
> The Current error is "NullReferenceException was Caught"
>
> Can any one advise what I am doing wrong?
>
> Darron
>
>
>
>
>
