New SQL Functions
New SQL functions provide compatibility with and ease migration from other database products. The new functions are as follows:
NVL
Specifies a value other than a null that is returned to your application when a null is encountered. For example in NVL(a,b), if 'a' is NULL then return 'b' else return 'a'.
This function is an alias for the IFNULL function.
NVL2
Returns different values based on whether the input value is NULL. For example, in NVL2(a,b,c), if 'a' is not null then return 'b' else return 'c'.
GREATEST
Returns the greatest of values in v1 through vN. Return type is that of the first parameter. If all of v1 through vN are NULL, then it returns NULL.
LEAST
Returns the least of values v1 through vN. Return type is that of the first parameter. If all of the values v1 through vN are NULL, then it returns NULL.
GREATER
Returns the greatest of values in v1 through vN. Return type is that of the first parameter. If any of v1 through vN are NULL, then it returns NULL.
LESSER
Returns the least of values v1 through vN. Return type is that of the first parameter. If any of the values v1 through vN are NULL, then it returns NULL.
For details, see the following sections in the SQL Reference Guide:
• NVL Function
• NVL2 Function
• IFNULL, NVL, NVL2 Result Data Types
• GREATEST, GREATER, LEAST, LESSER Functions