<gnewsham@gmail.com> wrote:

>Here is the code:
>
>64 If objdr.Item("BD") = "" Or objdr.Item("BD") Is DBNull.Value Then
>'test to see if result is blank or null
>65 strBD = "00000000" 'No birthdate found so set to 8 spaces
>66 Else
>67 strBD = objdr.Item("BD") 'All ok so leave as is
>68 End If
>
>Here is the error I get:
>
>System.InvalidCastException: Operator '=' is not defined for type
>'DBNull' and string "".
>at
>Microsoft.VisualBasic.CompilerServices.Operators.CompareObjectEqual(Object
>Left, Object Right, Boolean TextCompare)
> at my_project.Form1.Button1_Click(Object sender, EventArgs e) in C:
>\...\Form1.vb:line 64
>
>I am sure I have used this before with no problems, so am a little
>confused...
>
>Any thoughts?
>
>Thanks for your time.

On Sep 28, 11:06 am, Jack Jackson <jacknos...@pebbleridge.com> wrote:
> On Fri, 28 Sep 2007 17:19:56 -0000, Problematic coder
>
>
>
>
>
> <gnews...@gmail.com> wrote:
> >Here is the code:
>
> >64 If objdr.Item("BD") = "" Or objdr.Item("BD") Is DBNull.Value Then
> >'test to see if result is blank or null
> >65 strBD = "00000000" 'No birthdate found so set to 8 spaces
> >66 Else
> >67 strBD = objdr.Item("BD") 'All ok so leave as is
> >68 End If
>
> >Here is the error I get:
>
> >System.InvalidCastException: Operator '=' is not defined for type
> >'DBNull' and string "".
> >at
> >Microsoft.VisualBasic.CompilerServices.Operators.CompareObjectEqual(Object
> >Left, Object Right, Boolean TextCompare)
> > at my_project.Form1.Button1_Click(Object sender, EventArgs e) in C:
> >\...\Form1.vb:line 64
>
> >I am sure I have used this before with no problems, so am a little
> >confused...
>
> >Any thoughts?
>
> >Thanks for your time.
>
> The exception tells you what is wrong. You are trying to compare a
> DBNull to a string.
>
> Try changing the If to:
> If objdr.Item("BD") Is DBNull.Value OrElse objdr.Item("BD") = ""
> Then
>
> This tests for DBNull.Value first and changing Or to OrElse prevents
> the execution of the second test if the first is True.- Hide quoted text -
>
> - Show quoted text -