SELECT id,
(SELECT Score FROM Table_1 WHERE KeMu='数学' AND id=a.id)as 数学,
(SELECT Score FROM Table_1 WHERE KeMu='语文' AND id=a.id)AS 语文,
(SELECT Score FROM Table_1 WHERE KeMu='英语' AND id=a.id)AS 英语
FROM Table_1 a
GROUP BY a.id