MySql ::按日期时间最大分组

Now i want to group by with party and want to get data max date time i.e. idChat 55. How can i add group by in it because current group by giving me top row or any other if result table is large.CREATE TABLE IF NOT EXISTS `chat` ( `idCHAT` int(11) NOT NULL AUTO_INCREMENT, `USER_NAME` varchar(12) NOT NULL, `TEXT` varchar(512) DEFAULT NULL, `CURRENT_DATE_TIME` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, `CHAT_COUNTERPARTY` varchar(12) NOT NULL, PRIMARY KEY (`idCHAT`), KEY `CHAT_CHAT_COUNTERPARTY_IDX` (`CHAT_COUNTERPARTY`), KEY `CHAT_CURRENT_DATE_TIME_IDX` (`CURRENT_DATE_TIME`)) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=56 ;---- Dumping data for table `chat`--INSERT INTO `chat` (`idCHAT`, `USER_NAME`, `TEXT`, `CURRENT_DATE_TIME`, `CHAT_COUNTERPARTY`) VALUES(1, 'taruna', 'hello', '2014-10-30 11:57:11', 'pooja'),(2, 'pooja', 'hey', '2014-10-30 11:57:36', 'taruna'),(3, 'taruna', 'r u getting my msg', '2014-10-30 11:58:07', 'pooja'),(4, 'pooja', 'yes', '2014-10-30 11:58:12', 'taruna'),(5, 'pooja', 'yes', '2014-10-30 11:58:42', 'taruna'),(6, 'pooja', 'u will', '2014-10-30 11:59:04', 'taruna'),(7, 'taruna', ':)', '2014-10-30 12:00:17', 'pooja'),(8, 'pooja', 'why u dont reply me', '2014-10-30 12:00:21', 'taruna'),(9, 'pooja', '?', '2014-10-30 12:00:25', 'taruna'),(10, 'taruna', 'i want to buy your lappy', '2014-10-30 12:00:57', 'pooja'),(11, 'pooja', 'sure', '2014-10-30 12:01:19', 'taruna'),(12, 'taruna', 'fr hw much', '2014-10-30 12:01:34', 'pooja'),(13, 'pooja', '1 lakh', '2014-10-30 12:01:44', 'taruna'),(14, 'taruna', 'dimag khrb h???', '2014-10-30 12:02:23', 'pooja'),(15, 'taruna', 'der??', '2014-10-30 12:04:08', 'pooja'),(16, 'taruna', 'test', '2014-10-30 12:04:10', 'pooja'),(17, 'taruna', 'gv sm rply', '2014-10-30 12:11:18', 'pooja'),(18, 'pooja', 'test', '2014-10-30 12:11:32', 'taruna'),(19, 'taruna', '????', '2014-10-30 12:11:43', 'pooja'),(20, 'pooja', 'u got my msgs', '2014-10-30 12:11:48', 'taruna'),(21, 'taruna', 'anything else??', '2014-10-30 12:11:50', 'pooja'),(22, 'pooja', '??', '2014-10-30 12:11:54', 'taruna'),(23, 'taruna', 'yupp', '2014-10-30 12:12:08', 'pooja'),(24, 'taruna', 'hie', '2014-10-30 12:12:22', 'pooja'),(25, 'taruna', 'hlo', '2014-10-30 12:12:30', 'pooja'),(26, 'pooja', 'hi', '2014-10-30 12:13:09', 'taruna'),(27, 'pooja', 'hi', '2014-10-30 12:13:16', 'taruna'),(28, 'pooja', 'taruna', '2014-10-30 12:13:33', 'taruna'),(29, 'taruna', 'hws u', '2014-10-30 12:13:35', 'pooja'),(30, 'taruna', 'ring nhi ho rha phn', '2014-10-30 12:14:36', 'pooja'),(31, 'taruna', 'jai ho', '2014-10-30 12:15:52', 'pooja'),(32, 'pooja', 'I find error', '2014-10-30 12:17:33', 'taruna'),(33, 'pooja', 'u got it', '2014-10-30 12:17:45', 'taruna'),(34, 'taruna', 'yupppp', '2014-10-30 12:17:59', 'pooja'),(35, 'pooja', 'r u well??', '2014-10-30 12:19:40', 'taruna'),(36, 'pooja', 'hey reply', '2014-10-30 12:23:07', 'taruna'),(37, 'pooja', 'taruna', '2014-10-30 12:23:11', 'taruna'),(38, 'pooja', 'hey', '2014-10-30 12:23:15', 'taruna'),(39, 'pooja', 'hey', '2014-10-30 12:23:17', 'taruna'),(40, 'pooja', 'hey', '2014-10-30 12:23:18', 'taruna'),(41, 'pooja', 'hey', '2014-10-30 12:23:19', 'taruna'),(42, 'pooja', 'hi', '2014-10-30 12:24:06', 'taruna'),(43, 'pooja', 'taru una', '2014-10-30 12:31:44', 'taruna'),(44, 'taruna', 'its taruna', '2014-10-30 12:32:53', 'pooja'),(45, 'taruna', 'nt taruuna', '2014-10-30 12:34:22', 'pooja'),(46, 'pooja', 'whos u', '2014-10-30 12:35:42', 'taruna'),(47, 'taruna', 'Taruna Sharma', '2014-10-30 12:36:05', 'pooja'),(48, 'pooja', 'hi', '2014-10-30 12:39:27', 'taruna'),(49, 'taruna', 'hlo', '2014-10-30 12:40:00', 'pooja'),(50, 'pooja', 'hi', '2014-10-30 12:40:56', 'taruna'),(51, 'taruna', '133', '2014-10-30 12:41:38', 'pooja'),(52, 'taruna', '1234', '2014-10-30 12:41:41', 'pooja'),(53, 'pooja', 'hat', '2014-10-30 12:42:14', 'taruna'),(54, 'taruna', 'red hat', '2014-10-30 12:44:26', 'pooja'),(55, 'pooja', 'cat', '2014-10-30 12:45:48', 'taruna');推荐答案我用多个convos进行了测试，这应该很好.I tested this with multiple convos, this should be good.SELECT * FROM (SELECT *, IF(USER_NAME='taruna',CHAT_COUNTERPARTY,USER_NAME)AS `party` FROM `chat` WHERE `USER_NAME` = 'taruna' OR `CHAT_COUNTERPARTY` = 'taruna' ORDER BY `CURRENT_DATE_TIME` DESC) as `parties`GROUP BY `parties`.`party` 这篇关于MySql ::按日期时间最大分组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！