You should be aware that PHP and SQL have completely different concepts of null.
In php, null is a unique magic value that means "undefined", and if two things are null, then they are equal. <?php var_dump($a===$b) // bool(true) var_dump(NULL === NULL) // bool(true) Contrast this with SQL, where null is akin to "not yet known value" Consider: "SELECT NULL = NULL;" gives -------- | NULL | -------- In a SQL view of the world, that can be interpreted as: Are two not yet known values equal? and the answer is: "Not yet known" In sql, every comparison to NULL, yields another NULL. That is why 'SELECT * WHERE foo = NULL' doesn't do what you might expect. In fact that query is guaranteed to always return zero rows. It is a fact of life that pretty much every language handles NULL differently, and whenever I learn a new language, it is one of the first things I research. Regards, John Campbell _______________________________________________ New York PHP User Group Community Talk Mailing List http://lists.nyphp.org/mailman/listinfo/talk http://www.nyphp.org/show_participation.php
