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.
Syntax
Restrictions
The following restrictions apply when you use the NVL
function in the SELECT
command:
The replacement value (second expression) must be specified as character data.
The function does not support data conversions.
Example
This example replaces NULL
in the output for singalling_component
with the text "No component."
select nvl(signalling_component, 'No component') from incident;