mysql - 错误代码 1248，SQL 状态 42000 : Every derived table must have its own alias

Question

我正在 MySQL 上运行此查询。

Select Vendor, sum(Rate) as Rate
from (select case Vendor when 'NSN' then 'Nokia' else Vendor end as Vendor, Rate
from (  Select vendor ,(count(1) )*100/(Select count(id_incident)from incident where open_time between '2015-01-01'and'2015-01-30') as Rate from incident  where open_time between '2015-01-01'and'2015-01-30'group by upper (vendor) )) as y group by vendor;   

它给出了这个错误:

Error code 1248, SQL state 42000: Every derived table must have its own alias".

有什么问题吗？

Answer 1

您忘记为内部子查询指定别名。我选择了x

Select Vendor, sum(Rate) as Rate
from 
(
   select case Vendor when 'NSN' then 'Nokia' else Vendor end as Vendor, Rate
   from 
   (  
     Select vendor ,(count(1) )*100/(Select count(id_incident)from incident where open_time between '2015-01-01'and'2015-01-30') as Rate 
     from incident  
     where open_time between '2015-01-01'and'2015-01-30'
     group by upper (vendor) 
   ) as x
) as y 
group by vendor;