When you already have a not null column in a table click edit and uncheck the null checkbox.
You will get this error:
#1067 - Invalid default value for 'user'
The sql syntax that PHPMyAdmin is trying to use is:
ALTER TABLE `email` CHANGE `user` `user` VARCHAR( 255 ) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL DEFAULT NULL
It should be:
ALTER TABLE `email` CHANGE `user` `user` VARCHAR( 255 ) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL
It doesn't matter what kind of column it is. All the values are filled in. the problem is that it is using DEFAULT NULL at the end when you are removing NULL using the phpmyadmin interface.
The bug description is misleading, it should be "When you already have a null column...".
The "Default NULL" clause was generated because you did not change the default value after unchecking the null checkbox.
Moving to feature requests, to automate this change.
This requested feature was implemented in the repository and will be part of a future release; thanks for suggesting.