NVL2 lets you determine the value returned by a query based on whether a specified expression is null or not null. If expr1 is not null, then NVL2 returns expr2. If expr1 is null, then NVL2 returns expr3.
The argument expr1 can have any datatype. The arguments expr2 and expr3 can have any datatypes except LONG.
If the datatypes of expr2 and expr3 are different:
If expr2 is character data, then Oracle Database converts expr3 to the datatype of expr2 before comparing them unless expr3 is a null constant. In that case, a datatype conversion is not necessary. Oracle returns VARCHAR2 in the character set of expr2.
If expr2 is numeric, then Oracle determines which argument has the highest numeric precedence, implicitly converts the other argument to that datatype, and returns that datatype.
See Also:
Table 2-10, "Implicit Type Conversion Matrix" for more information on implicit conversion and "Numeric Precedence" for information on numeric precedenceThe following example shows whether the income of some employees is made up of salary plus commission, or just salary, depending on whether the commission_pct column of employees is null or not.
SELECT last_name, salary, NVL2(commission_pct, salary + (salary * commission_pct), salary) income FROM employees WHERE last_name like 'B%' ORDER BY last_name; LAST_NAME SALARY INCOME ------------------------- ---------- ---------- Baer 10000 10000 Baida 2900 2900 Banda 6200 6882 Bates 7300 8468 Bell 4000 4000 Bernstein 9500 11970 Bissot 3300 3300 Bloom 10000 12100 Bull 4100 4100