Replaces null (returned as a blank) with character data in the results of a query. If the first expression specified is null, then
NVL returns second expression specified. If first expression specified is not null, then
NVL returns the value of the first expression.
The following restrictions apply when you use the
NVL function in the
The replacement value (second expression) must be specified as character data.
The function does not support data conversions.
This example replaces
NULL in the output for
singalling_component with the text "No component."
select nvl(signalling_component, 'No component') from incident;