Re: setAssignedNull and setUnassignedNull

[Kevin Dean [TeamB]]

Clive Walden wrote:

>As a veteran SQL developer, I find these two methods confusing and wonder
>which to use and why.
>
>I have always believed in the mantra that NULL is NULL. It can be assigned
>NO meaning! Period.
>
>So, which method to use when wanting to set a Firebird column to null?
>
>Also, as neither Firebird nor any other SQL DB, of which I am aware, has
>any concept of this
>distinction, what difference can it possibly make?

At the database level there is no difference at all. The difference would
be at the application level; there may be a case (though I'm honestly hard
pressed to think of one right now) where you want to know if the column
has been deliberately assigned to. Initially, all columns are "unassigned
null"; as you move through the workflow of your application, you assign
some columns non-null values and may assign some columns null values (even
though they are already null) using setAssignedNull().

--
Kevin Dean [TeamB]
Dolphin Data Development Ltd.
http://www.datadevelopment.com/

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