NVL

Syntax

Purpose

If expr1 is null, NVL returns expr2; if expr1 is not null, NVL returns expr1. The arguments expr1 and expr2 can have any datatype. If their datatypes are different, Oracle converts expr2 to the datatype of expr1 before comparing them. The datatype of the return value is always the same as the datatype of expr1, unless expr1 is character data, in which case the return value's datatype is VARCHAR2.

Example

SELECT ename, NVL(TO_CHAR(COMM), 'NOT APPLICABLE')
   "COMMISSION" FROM emp
   WHERE deptno = 30;
 
ENAME      COMMISSION
---------- -------------------------------------
ALLEN      300
WARD       500
MARTIN     1400
BLAKE      NOT APPLICABLE
TURNER     0
JAMES      NOT APPLICABLE