这句SQL怎样优化比较好？

Question

select a.Protocol_name,a.Protocol_desc,sum(b.Protocol_count) from a,b where a.Protocol_ID=b.Protocol_ID group by a.Protocol_ID;

Answer 1

select a.Protocol_name,a.Protocol_desc,sum(b.Protocol_count) from a,b where a.Protocol_ID=b.Protocol_ID group by a.Protocol_ID,a.Protocol_desc

Answer 2

select a.Protocol_name,a.Protocol_desc,sum(b.Protocol_count) from a,b where a.Protocol_ID=b.Protocol_ID group by a.Protocol_Name,a.Protocol_desc

Answer 3

TO BlueskyWide(谈趣者) 兄：
       这样的写法是不行的，返回的a.Protocol_name,a.Protocol_desc,sum(b.Protocol_count) 与a.Protocol_ID是没有直接对应关系的
TO dihai2000(haifeng) 兄：
       发现结果不正确，但我找不到什么原因

Answer 4

select a.Protocol_name,a.Protocol_desc,sum(b.Protocol_count) 
   from a,b 
   where a.Protocol_ID=b.Protocol_ID (+)
   group by a.Protocol_ID,a.Protocol_desc

Answer 5

我知道原因了是我的a.Protocol_ID=b.Protocol_ID 在某些字段下不相等
比如原来ID=3A，但入库时写成了3a，就不等了，
大小写转换用什么函数？怎么改写上面的语句，谁答了就散分了

Answer 6

转换成大写的函数uppera.Protocol_ID=upper(b.Protocol_ID )
或
b.Protocol_ID=upper(a.Protocol_ID )

Answer 7

select a.Protocol_name,a.Protocol_desc,sum(b.Protocol_count) from a,b 
where upper(a.Protocol_ID)=upper(b.Protocol_ID) group by a.Protocol_Name,a.Protocol_desc