Question

本质上我有一个有两列的表

One    Two    
-----------
A       B   
B       C    
C       D

我想计算A到D的数量。

结果

Letter    Count  
---------------
   A        1
   B        2  
   C        2   
   D        1

我的代码现在是

Select one, count("") from table   
group by one   
union    
Select two, count("*") from table  
group by two

现在我正在

Letter    Count  
---------------
   A        1
   B        1  
   B        1  
   C        1  
   C        1  
   D        1

我该如何解决？

Answer 1

试试这个

SELECT Count(a), 
       a 
FROM  (SELECT cola a 
       FROM   table 
       UNION ALL 
       SELECT colb a 
       FROM   table) c 
GROUP  BY a

Answer 2

没有理由进行两次分组。

select letter, count(*) as total_cnt
from 
(
Select one as letter from table
union all
Select two as letter from table
) 
group by letter;

Answer 3

select letter, sum(total) from
(
Select one as letter, count(1) as total from tablename
group by one
union all
Select two as letter, count(1) as total from tablename
group by two) as t1
group by t1.letter 
order by t1.letter asc

Answer 4

您可以执行此操作

SELECT LETTER, count(*) AS _count FROM ( SELECT One AS Letter FROM Test UNION ALL SELECT Two AS Letter FROM Test ) T1 GROUP BY LETTER

从SQL服务器中的2列计数

4 个答案: