"NULL is a state, not a value" has been written lots of times in this
list. It is very different from any empty string, and I'd be greatly
surprised if they were considered equal even in Firebird 10.0 in 30
years time (other than as an non-default option).

I have heard about another database system that doesn't distinguish
between the two, but that was a database that had severe limitations.

Oh, one more thing. Please don't start a new thread by replying to an
old, it makes threading mess things up.

Set

bill_lam wrote:

> Some said in old sql standard, zero-length (empty) string will be
> converted to null, eg,
> update foo set bar=''
> will effectively become
> update foo set bar=null
>
> Is this true for FB1.5 and FB2 ?
>
> A related question, in DDL, is
> a varchar(10) default ''
> equivalent to
> bar varchar(10) default null
>
> (For your information MS Access does allow zero-length string)
>
> regards,
> bill