NVL replaces a null with a string. NVL returns the replacement string when the base expression is null, and the value of the base expression when it is not null.

To replace an expression with one value if it is null and a different value if it is not, use NVL2.

Return Value

Data type of the first argument


NVL(expr1, expr2)


expr1 is the base expression that is evaluated.

expr2 is the replacement string that is returned when expr1 is null.


NVL('First String', 'Second String') returns the value First String.

NVL(null, 'Second String') returns the value Second String.