選擇計數多列不同的列值

Question

我的表是這樣的：

ID   Status 
----------- ----------------- 
a   3 
b   3 
c   1 
d   2 
e   1 

我如何可以查詢它使得對每種狀態的數在1列：

Status=1 Status=2 Status=3 
-------- -------- -------- 
2   1   2 

是它有必要Select從多個Select的Count在這裏？ 注：狀態不是固定的，並且可以包含值除1,2和3

Answer 1

使用條件骨料

select count(case when Status = 1 then 1 end) as [Status=1], 
     count(case when Status = 2 then 1 end) as [Status=2], 
     count(case when Status = 3 then 1 end) as [Status=3] 
From yourtable 

相同的計數可通過SUM骨料

Sum(case when Status = 1 then 1 else 0 end) as [Status=1] 

Answer 2

嘗試此來實現，這是動態的

select 'Status = '+cast(Status as varchar(200)) Status,count(Status) Count from yourtable group by Status