XPost: comp.databases.oracle.misc, comp.databases.oracle.server   
   From: empty@zero.nil   
      
   Thu, 21 Oct 2004 18:54:29 -0700 DA Morgan    
   wrote:   
      
   > Two nulls should never be evaluated ... there is nothing to consider.   
   > So considering them the same or different is irrelevant.   
   >   
   > CREATE TABLE t (   
   > col1  NUMBER(1),   
   > col2  VARCHAR2(1),   
   > col3  DATE);   
   >   
   > INSERT INTO t (col1) VALUES (1);   
   > COMMIT;   
   >   
   > What sense would it make to compare col2 and col3?   
   > Would you consider them the same?   
      
   No. I wanted to stress the fact that   
   eval(NULL=NULL) "=" eval(NULL<>NULL) "=" "NULL"   
   where the doublequotes indicate metalanguage.   
      
   Unlike true and false, NULL acts on both levels   
   because it can be a column's "value" and can be   
   the result of a logical expression.   
      
   --   
   Frank Piron,   
   etfrankatkonaddotn   
   (leftrotate two)   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)