How to check an empty recordset?

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Sebastian Hort - 29 Oct 2004 12:28 GMT

If the database returns an NULLvalue, how can i check this?

I tried to check at objfield="" or NULL but it doesn`t work.

Any hints? thx

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Al Reid - 29 Oct 2004 12:31 GMT

> If the database returns an NULLvalue, how can i check this?
>
> I tried to check at objfield="" or NULL but it doesn`t work.
>
> Any hints? thx

Try the IsNull() Function.

If you know the field is a string type, you can simply append an empty string to the field value => rs(0).Value & ""

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Al Reid

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Sebastian Hort - 29 Oct 2004 13:48 GMT

thanks :)

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Val Mazur - 30 Oct 2004 02:17 GMT

Hi,

I would say that using IsNull function is better just because it was
designed to do this job. Empty string result during concatenation with NULL
is not documented and cannot be guaranteed and it does not work in a case of
numeric or date values.

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Val Mazur
Microsoft MVP

> thanks :)

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Al Reid - 30 Oct 2004 02:29 GMT

> Hi,
>
> I would say that using IsNull function is better just because it was
> designed to do this job. Empty string result during concatenation with NULL
> is not documented and cannot be guaranteed and it does not work in a case of
> numeric or date values.

I agree that empty string concatenation is not documented, but it can be
guaranteed to work with Null string values AND since VB is now at EOL the
behavior is not going to change. I think this still works with VB.Net as
well.

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Al Reid

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Val Mazur - 30 Oct 2004 02:53 GMT

Yes, it works in .NET as well because all NULL strings converted into empty
one during concatenation

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Val Mazur
Microsoft MVP

>> Hi,
>>
[quoted text clipped - 9 lines]
> behavior is not going to change. I think this still works with VB.Net as
> well.

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Douglas J. Steele - 29 Oct 2004 13:42 GMT

If you're asking how can you tell if a returned recordset has no rows in it,
check whether (rs.BOF = True And rs.EOF = True)

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Doug Steele, Microsoft Access MVP
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> If the database returns an NULLvalue, how can i check this?
>
> I tried to check at objfield="" or NULL but it doesn`t work.
>
> Any hints? thx

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Sebastian Hort - 29 Oct 2004 13:48 GMT

thanks :)

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Veign - 30 Oct 2004 01:43 GMT

There is no need to check for BOF as an empty recordset will set EOF.

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Chris Hanscom - Microsoft MVP (VB)
http://www.veign.com
--

> If you're asking how can you tell if a returned recordset has no rows in it,
> check whether (rs.BOF = True And rs.EOF = True)
[quoted text clipped - 4 lines]
> >
> > Any hints? thx

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VB Forum / Database Access / October 2004

How to check an empty recordset?