NVL

 
SYNTAX:
 
FUNCTION NVL(V                         : GENERIC : GEN1;
                            SUBSTITUTE   : GENERIC : GEN1)  :GENERIC:GEN1;
 
The nvl function returns either the input value or an alternate value in the case where the input
has a indeterminate value.
 
Parameters :
a) V is an expression which is of any type.
b) SUBSTITUTE is an expression which shall not evaluate to indeterminate .