Error is thus: "Cast from type 'DBNull' to type 'String' is not valid."
Simple, right? Well, no (or at least not for me).
Here's a function, followed by the calling code below:
Function GetDetails(ByVa l x As String, ByVal y as String)
Dim conn As New SqlConnection
("server=localh ost;uid=blah;pw d=blah;database =test")
Dim strSQL As String
Dim ds As New DataSet()
strSQL = "SELECT firstv.ocean_ca r, firstv.nr,first v.equip "
strSQL &= "FROM firstv INNER JOIN "
strSQL &= "lla ON firstv.doc + firstv.po = lla.doc + lla.po "
strSQL &= "WHERE firstv.doc = " & x & "AND firstv.po = " & y
Dim da As New SqlDataAdapter( strSQL, conn)
da.Fill(ds, "firstv")
Return ds.Tables("firs tv")
End Function
Calling code:
<asp:DataGrid runat=server id=dgDetails
DataSource=<%#
GetDetails(cont ainer.dataitem( "doc"),containe r.dataitem("po" ))%>
AutoGenerateCol umns=false>
<Columns>
<asp:BoundColum n DataField="ocea n_car"
HeaderText="Car rier"></asp:BoundColumn >
<asp:BoundColum n DataField="nr" HeaderText="Boo king"></asp:BoundColumn >
<asp:BoundColum n DataField="Equi p"
HeaderText="Equ ip"></asp:BoundColumn >
</Columns>
</asp:DataGrid>
The error occurs on the very first line of the calling code above.
Naturally, I thought "ah, it must be pulling in nulls from the doc and
po fields in firstv and that must be the cause." So I opened Query
Analyzer and changed all the nulls (in every column) into blanks. Still
got the error so I went back to QA and changed them all to "xyz."
Still, I got the error!! I thought maybe it had to do with the "ByVal"
statement in the function and switched to ByRef... still no go. Anyone
have any tips, please?
Thanks! And yes, I am still am relatively new to .NET. ;)
