[nycphp-talk] Need help understanding NULL
lists at nopersonal.info
lists at nopersonal.info
Sat Aug 29 23:09:11 EDT 2009
Kristina D. H. Anderson wrote:
>>> But in the case of a form, wouldn't you be validating the input before
>>> trying to insert the record? Sorry if I seem dense--I must be
>>> misunderstanding something.
>
> No, you are exactly right, and you'll want to use a combination of
> client-side (form) validation and good database design, and make
> decisions based on the individual application. But, you also need to
> be aware of other people's database design choices, and code around
> them. It's good to know that a blank string is not null when you need
> to populate a field that is supposed to be NOT NULL but actually has no
> value to be inserted...and that sounds insane, but I've seen stuff like
> this over the years, and sometimes it cannot be changed but only dealt
> with. :)
Ah, okay, I see your point now.
> Also sometimes you're not dealing with forms, let's say you have a web
> service that's sending you XML which gets processed and goes right into
> the database without your ever seeing it in the production environment
> (and this is getting more and more common these days, and there is just
> nobody sitting around reading a generated log of every response that
> comes in to check them, like I suggested you do in a test
> environment...that defeats the purpose of automatically inserting the
> data!), so the best way you're able to generate an error if fields are
> missing is if the query doesn't execute...this can happen, say, if the
> people sending you the data change something and don't bother to notify
> you...if your fields in the database will accept NULL inputs, you could
> look a week later and see missing data...there are a lot of different
> cases and all the solutions are different.
That makes perfect sense in the situation you describe.
*wonders if this programming stuff is ever going to get easier*
Bev ;)
More information about the talk
mailing list