Re: Weird Query

"AK" <AK_TIREDOFSPAM_at_hotmail.COM> wrote:

>>>You know, the '' is equivalent to NULL.
><<
>
>I have some reservations, such as:
>
>situation A:
>First Name: 'John'
>Middle Name: '' (unknown, not a required field)
>Last Name: 'Smith'
>
>situation B:
>First Name: 'Igor'
>Middle Name: '' (a known fact: no middle name at all. Russians do not
>have middle names. Patronymic names are not middle names)
>Last Name: 'Petrov'
>
>how would you distinguish between situations A and B?

You could not, nor would you need to...

A properly constructed where clause would return both of them, if desired..Empty strings are , by Oracle's definition, NULL. You could avoid that ( if you really, really needed to treat them differently for some reason) by setting a default value of ' ' ( 1 blank space string) for the Middle Name field; that way if no middle name is supplied, a 1 char string is inserted so that record would not be returned with an IS NULL test...  It would be returned if you used the
where ( Trim(Middle_Name) = '' or Middle_Name IS NULL ) construct Received on Mon Aug 01 2005 - 13:11:16 CDT