Re: The NULL in Oracle 7.3

Some rough info:

NULL is (sorry) NULL..
Its is a special value ( actually not a value, but...) for NO DATA - it is different from a blank ( a blank in a varchar2 is " "; NULL is equivalent to "" ) DATE fields must be BLANK if no date entered, not NULL NULL cannot be used in 'normal' comparison operators (=,>,<,etc) It is equal to nothing, it is NOT EQUAL to nothing, it has no > or < values to check against The only operators are IS NULL and IS NOT NULL You can use the NVL(possiblenull) function to handle it in formulas.. See any good book on Oracle for more details on the odd NULL thing..

mlaverd_at_hotmail.com (Marc-André Laverdière) wrote:

>Dear experts,
>
>Our student team is currently developping a project for a course and
>we are wondering about the NULL symbol.
>
>What exactly is the NULL?
>Can a VARCHAR2 and DATE information be NULL?
>
>This information would be helpful to determine our default values and
>constraints.
>
>Any information would be helpful.
>
>Marc-André Laverdière

-----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 80,000 Newsgroups - 16 Different Servers! =----- Received on Tue Jul 31 2001 - 18:12:43 CEST