> 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.