Can 'false' match some string in mysql?

Question

I have a table like this:

CREATE TABLE IF NOT EXISTS `session` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `token` varchar(32) NOT NULL,
  `profile` varchar(1000         


        

Answer 1

If you want to compare a boolean with a varchar, MySQL has to do some implicit type conversion. MySQL casts the varchar value to a boolean, checking only the first character.

If the character is a character or number 0, then the string is evaluated to 0, thus False.
If the character is a number different than 0, then the string is evaluted to 1, thus True (and not appearing in your result set)

The only thing to do is not to compare a string with a boolean, because it makes no sense.