Pada Tue, 27 Aug 2002 01:09:32 +0000
"Will K." <[EMAIL PROTECTED]> menulis :
> hello,
>
> Please dont tell me to RTFM on this one (cause I am already doing that), but
> for clarity's sake... can someone tell me what it means when you use NULL
> and NOT NULL in a query (specifically CREATE TABLE)? Also, when should I
> use them?
NULL mean empty value ... it's different if you insert value with "" ...
for example, you don't want to allow any record which doesn't have anything in
firstname field.
then you can define the field on table creation : firstname varchar not null
try to : insert into <table> (firstname) values (NULL); select * from <table> where
firstname is NULL;
--
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