Re: setting the where clause

Tom Lane wrote:
> johnf <jfabiani(at)yolo(dot)com> writes:
>
>> I'm am programming in python using the Dabo modules. www.dabodev.com if your
>> interested. Dabo is a framework that provides an easy way to build desktop
>> app's. To clear a data entry form. I have been setting the where clause
>> to "where 1=0". This of course retrieves 0 records and my form will display
>> nothing. It has been suggested that it might be better to set the where
>> clause to a primary key value that does not exist in the table "where PK
>> = -9999999".
>>
>
> Whoever said that doesn't know what they're talking about. It's not
> faster (because it forces an actual index probe to happen) and it's not
> safer (what if one day that PK value exists?).
>
> I'd personally go with "where false"; why not say what you mean rather
> than forcing humans and computers to deduce that the condition is
> constant false?
>
> regards, tom lane
>
>

Of course you would do the world a favour if you wrote a client-side
clear-the-screen routine that didn't pester the net and the server
un-necessarily.