mysql如何实现行转列

select * from 
(select sum(a.kills) '孙悟空' 
 from kills1 as a 
 LEFT JOIN tssrz as b 
 on a.user_id = b.id 
 WHERE b.user_name = '孙悟空' 
 GROUP BY b.user_name) e
 cross join 
 (select sum(a.kills) '猪八戒' 
 from kills1 as a 
 LEFT JOIN tssrz as b 
 on a.user_id = b.id 
 WHERE b.user_name = '猪八戒' 
 GROUP BY b.user_name) f

SELECT sum(case when user_name='孙悟空' then kills end) as '孙悟空',
 sum(case when user_name='猪八戒' then kills END) as '猪八戒',
 sum(case when user_name='沙和尚' then kills END) as '沙和尚'
 from tssrz as a
 join kills1 as b
 on a.id = b.user_id