"I don't know who my grandfather was. I am more interested in who his grandson will become."
Compatibility: NPS Extension
The NPS database software provides a function to substitute a NULL value in a column for another value. Earlier in this book we saw IS NULL and IS NOT NULL used within the WHERE clause. An additional way to test is to use the NVL function.
The purpose of this function is to compare the data value in the first column and when it contains a NULL, transform it for the life of the SQL statement to the second value.
The syntax for the NVL follows:
SELECTNVL(<column-name>, <column-or-literal-value> )
,<Aggregate> ( NVL(<column-name>, <column-or-literal-value> ))