选择哪个

Question

这是我的查询

select tabs.*, count.full_name  from ( 
 select noc, medal from olympic_medal_winners
)
pivot( 
 count(*) for medal in ( 'Gold' gold, 'Silver' silver, 'Bronze' bronze )
 ) tabs join COUNTRY count on tabs.NOC = count.short_name
order  by 2 desc, 3 desc, 4 desc;

它可以找到，这是输出：

我的问题是，为什么将查询更改为：

select tabs.noc, tabs.medal, count.full_name  from ( 
 select noc, medal from olympic_medal_winners
)
pivot( 
 count(*) for medal in ( 'Gold' gold, 'Silver' silver, 'Bronze' bronze )
 ) tabs join COUNTRY count on tabs.NOC = count.short_name
order  by 2 desc, 3 desc, 4 desc;

为什么显示此错误？

ORA-00904: "TABS"."MEDAL": invalid identifier
00904. 00000 -  "%s: invalid identifier"
*Cause:    
*Action:
Error at Line: 10 Column: 18

谢谢。