Ron Johnson wrote: > On 02/21/07 18:09, Erick Papadakis wrote: >> How would you like to use a database that has nuances like these -- >> http://forums.mysql.com/read.php?20,141120,141120#msg-141120 > > Huh? > > A blank string (does that mean '' or ' '?) is not NULL, so of > *course* it should pass the NOT NULL constraint. > > Or am I missing something? > Not sure what the OP was getting at but of course an empty string is not the same as a NULL. You have to follow that MySQL forum thread a few messages to see the real screwup. Upon learning that an empty string is not the same a a NULL, he adds a constraint: ALTER TABLE `tbl` CHANGE `col` `col` VARCHAR( 3 ) CHECK (`col` <>'') NOT NULL Unfortunately for him, this does not work either. The reason is clarified in the following message: "Currently MySQL accepts CHECK syntax but does not implement them. You can enforce such a rule at database level with a trigger, or at application level as another contributor suggested." Huh? Cheers, Steve
