SELECT * FROM foo WHERE id IS NULL;
Why you ask? Seems like a pretty normal thing to do.
MySQL has a known bug that will cause this to return the last row inserted into the DB, ie. something random, instead of what you are looking for. In reality, this was actually a design choice for MySQL. This was how they implemented the ability to figure out the ID for a row inserted with auto-increment. This is fixed in MySQL version 5.0.25 which will probably be in our next upgrade. If you have to use an older version of MySQL, do this:
def find_user_by_id(user_id)
return nil if user_id == nil
@user ||= User.find_by_id(user_id )
@user
end
not this:
def find_user_by_id(user_id)
@user ||= User.find_by_id(user_id )
@user
end
For more information, see...
http://bugs.mysql.com/bug.php
