Re: postgresql vs mysql

Erick Papadakis wrote:
> So how should I make a database rule in MySQL to not allow blank
> strings. Basically to REQUIRE a value for that column, whether it is
> NULL or NADA or VOID or whatever you wish to call it. I just want to
> make sure that something, some value, is entered for a column. Would
> appreciate any thoughts or pointers.
>
> Does PostgreSQL suffer from this oddity as well? This distinction
> between an empty string and a NULL? Could you also please give me an
> example of where this would be useful from a business logic
> standpoint? Why should a NULL be different from an empty string,
> what's the big mysterious difference?

Just an example:

middle name = '' mean no middle name
middle name = NULL mean "dB does not know if there is or not middle name"

I hope you understand the difference between empty and null. and for
numbers is other thing....in average for example null is not considered,
other values, yes

>
> Thanks.
>
>
>
> On 2/22/07, Ron Johnson <ron(dot)l(dot)johnson(at)cox(dot)net> wrote:
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>> On 02/21/07 18:09, Erick Papadakis wrote:
>> > How would you like to use a database that has nuances like these --
>> > http://forums.mysql.com/read.php?20,141120,141120#msg-141120
>>
>> Huh?
>>
>> A blank string (does that mean '' or ' '?) is not NULL, so of
>> *course* it should pass the NOT NULL constraint.
>>
>> Or am I missing something?
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