Re: NULLS and User Input WAS Re: multimaster

> Yeah, it is awful ;^)  However the existing system is equally awful
> because there is no way to enter NULL!

Consider this form :

First name :	Edgar
Middle name :	J.
Last name :	Hoover

Now, if someone has no middle name, like "John Smith", should we use NULL  
or "" for the middle name ?
NULL usually means "unknown" or "not applicable", so I believe we have to  
use the empty string here. It makes sense to be able to concatenate the  
three parts of the name, without having to put COALESCE() everywhere.

Now consider this form :

City	:	
State	:
Country	:

If the user doesn't live in the US, "State" makes no sense, so it should  
be NULL, not the empty string. There is no unnamed state. Also, if the  
user does not enter his city name, this does not mean he lives in a city  
whose name is "". So NULL should be used, too.

It is very context-dependent.