我現在有一個表CREATE TABLE `test` (
`id` int(10) NOT NULL auto_increment,
`c_id` int(10) NOT NULL,
`title` varchar(20) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=11 ;--
-- 导出表中的数据 `test`
-- INSERT INTO `test` VALUES (1, 1, 'aaa');
INSERT INTO `test` VALUES (2, 1, 'bbb');
INSERT INTO `test` VALUES (3, 2, 'ccc');
INSERT INTO `test` VALUES (4, 2, 'ddd');
INSERT INTO `test` VALUES (5, 2, 'eee');
INSERT INTO `test` VALUES (6, 3, 'fff');
INSERT INTO `test` VALUES (7, 3, 'qqq');
INSERT INTO `test` VALUES (8, 3, 'wwww');
INSERT INTO `test` VALUES (9, 3, 'ttt');
INSERT INTO `test` VALUES (10, 4, 'ggg');我要查詢得到分别 c_id 显示 2条 不夠2條的就只顯示一條.如果有多的則只顯示2條.
`id` int(10) NOT NULL auto_increment,
`c_id` int(10) NOT NULL,
`title` varchar(20) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=11 ;--
-- 导出表中的数据 `test`
-- INSERT INTO `test` VALUES (1, 1, 'aaa');
INSERT INTO `test` VALUES (2, 1, 'bbb');
INSERT INTO `test` VALUES (3, 2, 'ccc');
INSERT INTO `test` VALUES (4, 2, 'ddd');
INSERT INTO `test` VALUES (5, 2, 'eee');
INSERT INTO `test` VALUES (6, 3, 'fff');
INSERT INTO `test` VALUES (7, 3, 'qqq');
INSERT INTO `test` VALUES (8, 3, 'wwww');
INSERT INTO `test` VALUES (9, 3, 'ttt');
INSERT INTO `test` VALUES (10, 4, 'ggg');我要查詢得到分别 c_id 显示 2条 不夠2條的就只顯示一條.如果有多的則只顯示2條.
[征集]分组取最大N条记录方法征集,及散分....
INSERT INTO `test` VALUES (1, 1, 'aaa');
INSERT INTO `test` VALUES (2, 1, 'bbb');
INSERT INTO `test` VALUES (3, 2, 'ccc');
INSERT INTO `test` VALUES (4, 2, 'ddd');
INSERT INTO `test` VALUES (6, 3, 'fff');
INSERT INTO `test` VALUES (7, 3, 'qqq');
INSERT INTO `test` VALUES (10, 4, 'ggg');