gistfile1.sql

# Run each statement separately, not all at once

CREATE TABLE `posts` (
  `post_id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `user_id` int(10) unsigned NOT NULL DEFAULT '0',
  `date` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  `active` tinyint(2) NOT NULL DEFAULT '0',
  PRIMARY KEY (`post_id`)
) ENGINE=InnoDB AUTO_INCREMENT=190 DEFAULT CHARSET=utf8;

CREATE TABLE `post_bids` (
  `bid_id` bigint(20) NOT NULL AUTO_INCREMENT,
  `post_id` bigint(20) unsigned NOT NULL,
  `amount` int(11) unsigned NOT NULL,
  `date` datetime DEFAULT NULL,
  PRIMARY KEY (`bid_id`),
  KEY `post_id` (`post_id`),
  CONSTRAINT `post_bids_ibfk_1` FOREIGN KEY (`post_id`) REFERENCES `posts` (`post_id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=13 DEFAULT CHARSET=latin1;

INSERT INTO posts
(post_id, user_id, date)
VALUES
(1, 23, NOW());

INSERT INTO post_bids
(post_id, amount, date)
VALUES
(1, 0, NOW()),
(1, 1, NOW()+ INTERVAL 1 DAY),
(1, 2, NOW()+ INTERVAL 2 DAY),
(1, 3, NOW()+ INTERVAL 3 DAY),
(1, 5, NOW()+ INTERVAL 4 DAY),
(1, 123, NOW()+ INTERVAL 5 DAY);

SELECT user_id, amount FROM post_bids 
    JOIN posts ON posts.post_id = post_bids.post_id 
    GROUP BY user_id
    ORDER BY post_bids.`date` DESC
    LIMIT 3;

gistfile2.txt

Getting:
----------------
user_id | amount
----------------
23      | 0


Expecting:
-----------------
user_id | amount
-----------------
23      | 123