一道sql面试题

SELECT NAME ,
SUM(CASE WHEN class='html' THEN score ELSE 0  END ) html,
SUM(CASE WHEN class='js' THEN score ELSE 0 END) js,
SUM(CASE WHEN class='sql' THEN score ELSE 0 END) 'sql'
 FROM score  GROUP BY NAME ;

上面是行转列！！！！！