The below are the Null value functions in Tearadata. One is "NVL" and another one is "NVL2". These two functions are part of Teradata SQL.
NVL -The NVL function replace null value with a string or numeric value. This is the functionality is same as Teradata function NULLIF. It requires two arguments. If the value is not null, it will not do anything.
The best SQL NVL function:
SELECT NVL (NULL,'USA'), NVL('SPAIN','USA');
Also Read: Top 70 Teradata Interview Questions
The NVL2 function: Returns one of two specified values (arguments#2 and Arguments#3) based on weather the first arguments in NULL or not. It requires three arguments. The rule is as follows:
If expression 1 is not null, expression 2 is returned
If expression 1 is null, expression 3 is returned
The best NVL2 example
SELECT NVL2(NULL,'FRANCE','SPAIN'), NVL2('ENGLAND','FRANCE','SPAIN')