Sunday, 25 September 2016

All You Need To Know About NULL Value Functions

Teradata SQL Null functions
NULL functions
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');
-----------
USA  SPAIN

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')
-------------------
SPAIN   FRANCE

No comments:

Post a Comment

5 Top Teradata DATE functions read now

  The following are the list of DATE functions. These are very frequently being used in Teradata. Current DATE The following statem...