Difference between revisions of "IFNULL()"
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Revision as of 08:09, 4 February 2013
Contents
Purpose
Function to specify an alternative value for a null expression
Syntax
IFNULL(<expr1>,<expr2>)
See Also
EMPTY(), ETOS(), EVL(), ISNULL(), NVL(), SET NULL, SET NULLDISPLAY
Description
The IFNULL() function evaluates the expression in <expr1>, and if the expression does not evaluate to NULL, the evaluated result is returned. If the expression in <expr1> does evaluate to NULL, the expression in <expr2> is evaluated. If <expr2> does not evaluate to NULL, the evaluated result is returned. If both <expr1> and <expr2> evaluate to NULL, the NVL() function returns NULL.
Example
set null on CREATE TABLE nullon (firstname c(20), lastname c(20)) INSERT INTO nullon (lastname) VALUES ("Smith") SELECT lastname, ifnull(firstname,"Unknown") from nullon
