Re: Oracle's treatment of null and empty string

From: ragoczy_at_SolarBears.fan.org (Paul Jackson) >> I'm a developer and our DBA told us today that Oracle 7.3 makes no distinction between a null value and an empty string in varchar or varchar2 column. <<

Oracle handles null values in accordance to the ANSI standard. A null value indicateds the absence of a value, i.e., it is unknown. Two null columns do not compare equal, but return a null. The result of any comparision is true, false, or null. I like to think of it as true or 'not true' instead of false.

An empty string is often called a null string, and a null is a null by any name.

Your DBA was correct. The Application Developers Guide explains the data types very well. You may want to see if your account has one. It has a lot of good charts in it that can help you with you code.

Mark Powell -- Oracle 7 Certified DBA
- The only advice that counts is the advice that you follow so follow your own advice - Received on Sat Feb 14 1998 - 00:00:00 CST