Better syntax?

[MLH]

If Not IsNull(DLookup( "[YR]", "tblCars", "[VID]=GetCurrVID()") ) Then

If DLookup("[YR]", "tblCars", "[VID]=GetCurrVID()") Then

Of the above 2 syntax variations, is the 2nd unacceptable? I use the
former because I seem to remember suggestions in this forum that
discouraged the latter. But I tire of it. To me, the latter is more
readily understood because there's no double negative to deal with.

[Rick Brandt]

Re: Better syntax?

MLH wrote:[color=blue]
> If Not IsNull(DLookup( "[YR]", "tblCars", "[VID]=GetCurrVID()") ) Then
>
> If DLookup("[YR]", "tblCars", "[VID]=GetCurrVID()") Then
>
> Of the above 2 syntax variations, is the 2nd unacceptable? I use the
> former because I seem to remember suggestions in this forum that
> discouraged the latter. But I tire of it. To me, the latter is more
> readily understood because there's no double negative to deal with.[/color]

If the value of [YR] returned is zero or null then the expression will not work
as expected.

If the criteria finds no rows you will get null back (not false).

Using DCount() instead of DLookup() would solve both of those problems, but
might take a few more clicks to resolve.

--
Rick Brandt, Microsoft Access MVP
Email (as appropriate) to...
RBrandt at Hunter dot com

[paii, Ron]

Re: Better syntax?


"MLH" <CRCI@NorthStat e.net> wrote in message
news:115q62dcn3 ggut9vsdsuqa30v j6a7t30cb@4ax.c om...[color=blue]
> If Not IsNull(DLookup( "[YR]", "tblCars", "[VID]=GetCurrVID()") ) Then
>
> If DLookup("[YR]", "tblCars", "[VID]=GetCurrVID()") Then
>
> Of the above 2 syntax variations, is the 2nd unacceptable? I use the
> former because I seem to remember suggestions in this forum that
> discouraged the latter. But I tire of it. To me, the latter is more
> readily understood because there's no double negative to deal with.[/color]

If NZ(DLookup("[YR]", "tblCars", "[VID]=GetCurrVID()") , 0) <> 0 Then

Assuming [YR] = 0 is not acceptable ,

[MLH]

Re: Better syntax?

On Fri, 19 May 2006 02:39:14 GMT, "Rick Brandt"
<rickbrandt2@ho tmail.com> wrote:
[color=blue]
>MLH wrote:[color=green]
>> If Not IsNull(DLookup( "[YR]", "tblCars", "[VID]=GetCurrVID()") ) Then
>>
>> If DLookup("[YR]", "tblCars", "[VID]=GetCurrVID()") Then
>>
>> Of the above 2 syntax variations, is the 2nd unacceptable? I use the
>> former because I seem to remember suggestions in this forum that
>> discouraged the latter. But I tire of it. To me, the latter is more
>> readily understood because there's no double negative to deal with.[/color]
>
>If the value of [YR] returned is zero or null then the expression will not work
>as expected.
>
>If the criteria finds no rows you will get null back (not false).
>
>Using DCount() instead of DLookup() would solve both of those problems, but
>might take a few more clicks to resolve.[/color]
=============== =============== =============
I see your point. I can rid myself of the dbl-neg situation
easily enough by reversing the Do This or Do That. But
I think I like your DCount suggestion better.

If [double-negative condition] Then
Do THIS if true
Else
Do THAT if false
Endif


If [straight-forward condition w/ NO dbl-neg] Then
Do THAT if true
Else
Do THIS if false
Endif