Syntax
nvl::=
Text description of nvl
Purpose
NVL lets you replace a null (blank) with a string in the results of a query. If expr1 is null, then NVL returns expr2. If expr1 is not null, then NVL returns expr1. The arguments expr1 and expr2 can have any datatype. If their datatypes are different, then 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 and is in the character set of expr1.
Examples
The following example returns a list of employee names and commissions, substituting "Not Applicable" if the employee receives no commission:
SELECT last_name, NVL(TO_CHAR(commission_pct), 'Not Applicable')
"COMMISSION" FROM employees
WHERE last_name LIKE 'B%'
ORDER BY last_name;
LAST_NAME COMMISSION
------------------------- ----------------------------------------
Baer Not Applicable
Baida Not Applicable
Banda .1
Bates .15
Bell Not Applicable
Bernstein .25
Bissot Not Applicable
Bloom .2
Bull Not Applicable
