如何做数据库的行列转置

CREATE TABLE `score_collect` (   `std_id` int(10) NOT NULL,   `course_id` int(11) NOT NULL,   `score` varchar(255) DEFAULT NULL,   PRIMARY KEY (`std_id`,`course_id`), )

INSERT INTO `score_collect` VALUES ('2012508082', '2', '20'); INSERT INTO `score_collect` VALUES ('2012508082', '3', '10'); INSERT INTO `score_collect` VALUES ('2012508082', '4', '30'); INSERT INTO `score_collect` VALUES ('2012508084', '2', '21'); INSERT INTO `score_collect` VALUES ('2012508084', '3', '11'); INSERT INTO `score_collect` VALUES ('2012508084', '4', '31');

SELECT std_id,GROUP_CONCAT(course_id) AS course_id,GROUP_CONCAT(score) AS score FROM `score_collect` GROUP BY std_id;

//$list=array(array('std_id'=>'2012508082','course_id'=>'2,3,4','score'=>'20,10,30'),array('std_id'=>'2012508084','course_id'=>'2,3,4','score'=>'21,11,31'),);foreach($list as $key=>$val){	$course_id_arr=explode(',',$val['course_id']);	$score_arr=explode(',',$val['score']);	unset($list[$key]['course_id']);	unset($list[$key]['score']);	foreach($course_id_arr as $key1=>$val1)	{		$list[$key][$val1]=$score_arr[$key1];	}}print_r($list);