Order query result by latest updated date - mysql

Question

i am working on two tables,
CREATE TABLE IF NOT EXISTS `users` (
`userid` INT NOT NULL AUTO_INCREMENT ,
`fname` VARCHAR(45) NOT NULL ,
`lname` VARCHAR(45) NOT NULL ,
`usernick` VARCHAR(45) NOT NULL ,
PRIMARY KEY (`userid`) ,
UNIQUE INDEX `usernick_UNIQUE` (`usernick` ASC) )
ENGINE = InnoDB;
CREATE TABLE IF NOT EXISTS `messages` (
`messageid` INT NOT NULL AUTO_INCREMENT ,
`sendid` INT NOT NULL ,
`recid` INT NOT NULL ,
`message` VARCHAR(1000) NOT NULL ,
`date` TIMESTAMP NULL ,
PRIMARY KEY (`messageid`) ,
INDEX `sender_fk_idx` (`sendid` ASC) ,
INDEX `reciever_fk_idx` (`recid` ASC) ,
CONSTRAINT `sender_fk`
FOREIGN KEY (`sendid` )
REFERENCES `users` (`userid` )
ON DELETE CASCADE
ON UPDATE CASCADE,
CONSTRAINT `reciever_fk`
FOREIGN KEY (`recid` )
REFERENCES `users` (`userid` )
ON DELETE CASCADE
ON UPDATE CASCADE)
ENGINE = InnoDB;
and want a list of user on basis if their last sent message. Eg.
select U.fname,U.lname,U.usernick from messages as M natural join users as U where M.sendid = U.userid and M.recid={$_SESSION['user_id']} group by U.usernick ORDER BY M.date DESC
EXAMPLE:
name msg sent to "RON" on
Alpha 17 aug
Beta 18 aug
Alpha 19 aug
Gamma 20 aug
SO i want a list like,
gamma (last msg on 20)
alpha (last msg on 18)
beta (last msg on 19)
SEE LINK http://sqlfiddle.com/#!2/9dca2/2/0

Answer 1

You almost have it. You just need max(m.date) in the order by clause. Otherwise, an arbitrary date is chosen:
select U.fname,U.lname,U.usernick
from messages as M join
users as U
on M.sendid = U.userid
where M.recid={$_SESSION['user_id']}
group by U.usernick
ORDER BY max(M.date) DESC
I also fixed the join syntax. It is best to avoid natural joins -- that is, be explicit about the join condition. You do this anyway, so I switched the condition to an on clause and the natural join to a join.