Mysql ISNULL function
by Rekha[ Edit ] 2010-01-28 15:23:09
ISNULL():
Syntax:ISNULL(expression);
If expr is NULL, ISNULL() returns 1, otherwise it returns 0.
mysql> SELECT ISNULL(1+1);
-> 0
mysql> SELECT ISNULL(1/0);
-> 1
ISNULL() can be used instead of = to test whether a value is NULL.
SELECT ISNULL(field,0) FROM TABLE
If the field is not null, returns its value; otherwise, 0.
