Heim > Artikel > Backend-Entwicklung > 怎么做数据库的行列转置?
如何做数据库的行列转置??
thinkphp和mysql。数据库如图所示:
建表的sql语句如下:
<br />CREATE TABLE `score_collect` (<br /> `std_id` int(10) NOT NULL,<br /> `course_id` int(11) NOT NULL,<br /> `score` varchar(255) DEFAULT NULL,<br /> PRIMARY KEY (`std_id`,`course_id`),<br /> )<br />
<br />INSERT INTO `score_collect` VALUES ('2012508082', '2', '20');<br /> INSERT INTO `score_collect` VALUES ('2012508082', '3', '10');<br /> INSERT INTO `score_collect` VALUES ('2012508082', '4', '30');<br /> INSERT INTO `score_collect` VALUES ('2012508084', '2', '21');<br /> INSERT INTO `score_collect` VALUES ('2012508084', '3', '11');<br /> INSERT INTO `score_collect` VALUES ('2012508084', '4', '31');<br />
<br />SELECT std_id,GROUP_CONCAT(course_id) AS course_id,GROUP_CONCAT(score) AS score FROM `score_collect` GROUP BY std_id;<br />
<br />//$list=array(array('std_id'=>'2012508082','course_id'=>'2,3,4','score'=>'20,10,30'),array('std_id'=>'2012508084','course_id'=>'2,3,4','score'=>'21,11,31'),);<br /><br />foreach($list as $key=>$val)<br />{<br /> $course_id_arr=explode(',',$val['course_id']);<br /> $score_arr=explode(',',$val['score']);<br /> unset($list[$key]['course_id']);<br /> unset($list[$key]['score']);<br /> foreach($course_id_arr as $key1=>$val1)<br /> {<br /> $list[$key][$val1]=$score_arr[$key1];<br /> }<br />}<br /><br />print_r($list);<br />