Re: [Q] Porting SQL to Oracle

Billy Verreynne (vslabs_at_onwe.co.za) wrote:
: andrewst_at_onetel.net.uk (Tony)

: > > Define what value is in between the quotes for ''.
: >
: > It is the empty string. It is the character analogue of the number 0.
: > It is a string of 0 characters.

: Char(0) still takes up a single byte or character in a string. A
: string with '' does not contain a Char(0). The string is undefined as
: it does not contain anything.. i.e. the string does not exist. It has
: not been constructed.

That's like saying that a bank account doesn't exist unless it has money in it.

A string is not a character, it is a set of characters. The number of characters in the set is one of it's attributes. A set of characters that has no charactes in it is still a perfectly good set, just like the bank account with no money is still a bank account.

The bank account doesn't magically cease to exist just because it contains no money - the string doesn't magically cease to exist just because it contains no characters.

In all other aspects of computer use, programmers seems to be able to work with strings that can have zero characters in them. Received on Thu Jun 12 2003 - 17:07:27 CDT