Question

Select Category,COUNT(HId) as Ticket 
from tblHelpdeskCalls 
Group by Category

Select Category,COUNT(HId) as Processing 
from tblHelpdeskCalls 
where CallStatus='Processing' 
Group by Category

Select Category, COUNT(HId) as Accepted 
from tblHelpdeskCalls 
where CallStatus='Accepted' 
Group by Category

等

将其显示在单个声明中

Answer 1

使用条件聚合：

select category,
       count(*) Ticket,
       sum(case when CallStatus = 'Processing' then 1 else 0 end) Processing,
       sum(case when CallStatus = 'Accepted' then 1 else 0 end) Accepted
from tblHelpdeskCalls t
group by category;

Answer 2

您仍然可以使用COUNT：

SELECT category,
       Ticket     = COUNT(*),
       Processing = COUNT(CASE WHEN CallStatus = 'Processing' THEN HId END),
       Accepted   = COUNT(CASE WHEN CallStatus = 'Accepted'   THEN HId END)
FROM tblHelpdeskCalls
GROUP BY category;

匹配CASE时WHEN的默认值为NULL，汇总函数跳过NULL值。

Answer 3

首先，我们按类别和计数进行分组：

select category,
       count(*) Ticket
  from tblHelpdeskCalls
 group by category;

其次，第二，它区分了CallStatus（Processing / Accepted）的情况。我们可以使用＆＃34; case＆＃34;或＆＃34;解码＆＃34;：

使用＆＃34;＆＃34; （由Yogesh Sharma和lad2025提出）：

select category,
       count(*) Ticket,
       sum(case when CallStatus = 'Processing' then 1 else 0 end) Processing,
       sum(case when CallStatus = 'Accepted' then 1 else 0 end) Accepted
  from tblHelpdeskCalls
 group by category;

使用＆＃34;解码＆＃34;：

select category,
       count(*) Ticket,
       sum( decode(CallStatus, 'Processing', 1, 0) ) Processing,
       sum( decode(CallStatus, 'Accepted'  , 1, 0) ) Accepted
  from tblHelpdeskCalls
 group by category;

我们可以使用多计数（列）与SQL Server中每个计数的cluase

3 个答案: