[Resolved] Should I use NULL values in the table?

apenster

High!

the problem: user can supply info. some information is optional like age. However he can enter it later during the course.

so i want the field age in my sql table to be empty but also editable to some value in later stage.

Should I set the age column in my table to null or not null?

many thanks!

thorpe

you need to allow nulls otherwise any field that is empty will cause an error during your insert.

apenster

Originally posted by thorpe
you need to allow nulls otherwise any field that is empty will cause an error during your insert.

You mean when a user enters his age and the age field is empty and not null there will be an error. You mean that?

thanks

thorpe

yep

apenster

why?

Drakla

I try to avoid using NULL if it's not necessary to the application as it adds an extra byte to every field that you allow it on, petty I know, especially as storage isn't a premium much anymore. But - if you're willing to allow a zero to be your nothing value then you can allow blank inserts by quoting the inserts.

create temporary table cah (id int not null default 0);

insert into cah VALUES (3), (1), ('');

select * from cah;

Will give you 3, 1, 0. If you don't like the extra hazard of having to quote the input, which I don't like myself, you could do somehting like

$age = (int)$_GET['age'];

On your input, which will avoid possible errors on numeric fields that you haven't checked for non numeric.

thorpe

so that it allows null values. (empty fields).

apenster

thanks for the input. RESOLVED