RE: empty string = null?

[MacGregor, Ian A.]

The promise/threat to treat empty strings differently from nulls has been in the documentaion since at least Oracle 7.3.

 

Ian MacGregor

Stanford Linear Accelerator Center

[EMAIL PROTECTED]

-----Original Message-----
From: Khedr, Waleed [mailto:[EMAIL PROTECTED]]
Sent: Thursday, April 11, 2002 6:33 PM
To: Multiple recipients of list ORACLE-L
Subject: RE: empty string = null?

I feel I had the same dream. Anyway this from Oracle 9i doc:
Nulls

"If a column in a row has no value, then the column is said to be null, or to contain a null. Nulls can appear in columns of any datatype that are not restricted by NOT
NULL or PRIMARY KEY integrity constraints. Use a null when the actual value is not known or when a value would not be meaningful.

Do not use null to represent a value of zero, because they are not equivalent. (Oracle currently treats a character value with a length of zero as null. However, this
may not continue to be true in future releases, and Oracle recommends that you do not treat empty strings the same as nulls.) Any arithmetic expression containing a
null always evaluates to null. For example, null added to 10 is null. In fact, all operators (except concatenation) return null when given a null operand."


Regards,

Waleed

-----Original Message-----
From: Jonathan Gennick [mailto:[EMAIL PROTECTED]]
Sent: Thursday, April 11, 2002 8:44 PM
To: Multiple recipients of list ORACLE-L
Subject: empty string = null?


Oracle has always treated empty strings (e.g.: '') as nulls.
As I sit here and think about this, I can convince myself
that I read somewhere that Oracle9i provided an option to
treat empty strings not as nulls, but truly as empty
strings. Is this the case, or is my mind manufacturing
memories?

Jonathan Gennick --- Brighten the corner where you are
mailto:[EMAIL PROTECTED]
http://Gennick.com * http://MichiganWaterfalls.com *
http://ValleySpur.com
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Author: Jonathan Gennick
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