hi all

when creating tables,

in my sql i have used create table
CREATE TABLE `users` (
  `user_id` int(11) NOT NULL auto_increment,
  `user_name` varchar(50) NOT NULL,
  `first_name` varchar(50) default NULL,
  `middle_name` varchar(50) default NULL,
  `last_name` varchar(50) default NULL,
  `password` varchar(50) default NULL,
  `salt` varchar(50) default NULL,
  `secret_question` varchar(255) default NULL,
  `secret_answer` varchar(255) default NULL,
  `creator` int(11) default NULL,
  `date_created` datetime NOT NULL default '0000-00-00 00:00:00',
  `changed_by` int(11) default NULL,
  `date_changed` datetime default NULL,
  `voided` tinyint(1) NOT NULL default '0',
  `voided_by` int(11) default NULL,
  `date_voided` datetime default NULL,
  `void_reason` varchar(255) default NULL,
  PRIMARY KEY  (`user_id`),
  KEY `users_user_creator` (`creator`),
  KEY `users_user_who_changed_user` (`changed_by`),
  KEY `users_user_who_voided_user` (`voided_by`),
  CONSTRAINT `users_user_creator` FOREIGN KEY (`creator`) REFERENCES
`users` (`user_id`),
  CONSTRAINT `users_user_who_changed_user` FOREIGN KEY (`changed_by`)
REFERENCES `users` (`user_id`),
  CONSTRAINT `users_user_who_voided_user` FOREIGN KEY (`voided_by`)
REFERENCES `users` (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;


while in pgsql i am thinking of to use the same as follows:

CREATE TABLE users (
  user_id int(11) NOT NULL serial,
  user_name varchar(50) NOT NULL,
  first_name varchar(50) default NULL,
  middle_name varchar(50) default NULL,
  last_name varchar(50) default NULL,
  password varchar(50) default NULL,
  salt varchar(50) default NULL,
  secret_question varchar(255) default NULL,
  secret_answer varchar(255) default NULL,
  creator int(11) default NULL,
  date_created datetime NOT NULL default '0000-00-00 00:00:00',
  changed_by int(11) default NULL,
  date_changed datetime default NULL,
  voided smallint(1) NOT NULL default '0',
  voided_by int(11) default NULL,
  date_voided datetime default NULL,
  void_reason varchar(255) default NULL,
  PRIMARY KEY  (user_id),
  KEY users_user_creator (creator),
  KEY users_user_who_changed_user (changed_by),
  KEY users_user_who_voided_user (voided_by),
  CONSTRAINT users_user_creator FOREIGN KEY (creator) REFERENCES users
(user_id),
  CONSTRAINT users_user_who_changed_user FOREIGN KEY (changed_by)
REFERENCES users (user_id),
  CONSTRAINT users_user_who_voided_user FOREIGN KEY (voided_by)
REFERENCES users (user_id)
) ;

will that be valid to create a table like this
if no what all have to  be replaced
thanks for any help


Regards
 kusuma.p