SQL百分比

Question

我有表INCIDENT与行

TICKETID ACTUALFINISH   TARGETFINISH 
100  2012-03-01 11:11:11 2012-02-01 11:11:11 
101  2012-03-01 11:11:11 2012-01-01 11:11:11 
102  2012-04-01 11:11:11 2012-06-01 11:11:11 
103  2012-05-01 11:11:11 2012-07-01 11:11:11 
104  null      null 

我想在行的百分比，其中target finish比actual finish和相对较大。

因此，对于这个表的结果将是（不涉及空值）：

SLA PERCENTAGE 
YES 50 
NO  50 

我写的SQL查询，但我不断收到错误。我不知道错误在哪里。

我第一次得到的不是地方AFIS比TF大的记录总数，然后AF比TF

with HELPTABLE as 
    (select count(*) as Total 

from incident as incident4 

where incident4.targetfinish is not null and incident4.actualfinish is not null) 


select distinct case when incident.targetfinish>incident.actualfinish then 
       dec(((select count(*) 

from incident as incident1 

where incident1.targetfinish is not null and incident1.actualfinish is not null )),10,2)/HELPTABLE.Total*100 

when incident.targetfinish<incident.actualfinish then 

       dec(((select count(*) 

from incident as incident2 

where incident2.targetfinish is not null and incident2.actualfinish is not null )),10,2)/HELPTABLE.Total*100 
        end as Percentage, 

     case when incident.targetfinish>incident.actualfinish then 'Yes' 
      when incident.targetfinish<incident.actualfinish then 'No' 
     end as SLA 



from incident 

where incident.targetfinish is not null and incident.actualfinish is not null 

如果有人知道什么是错误的感谢小！

[Error Code: -206, SQL State: 42703] DB2 SQL Error: SQLCODE=-206, SQLSTATE=42703, SQLERRMC=HELPTABLE.TOTAL, DRIVER=3.57.82)

Answer 1

select 'YES' as SLA, 
(SUM(case when targetfinish > actualfinish then 1.0 else 0.0 end)/count(*)) * 100 as PERCENTAGE 
from incident 
where targetfinish is not null and actualfinish is not null 
union 
select 'NO' as SLA, 
(SUM(case when targetfinish <= actualfinish then 1.0 else 0.0 end)/count(*)) * 100 as PERCENTAGE 
from incident 
where targetfinish is not null and actualfinish is not null 

http://sqlfiddle.com/#!3/2e903/18