Question

我有一张这样的表：

ID     Diagnosis   
---------------
1       d1
1       d2
1       d3         
2       d1
2       d3
2       d4
3       d1
3       d2

我想计算同时包含ID和d1的唯一d2。

所需的输出像这样

total    
------
2

如何编写SQL代码来实现这一目标？

Answer 1

您可以使用几个in条件：

SELECT COUNT(DISTINCT id)
FROM   my_table
WHERE  id IN (SELECT id FROM my_table WHERE diagnosis = 'id1') AND
       id IN (SELECT id FROM my_table WHERE diagnosis = 'id2')

Answer 2

这是MySQL的解决方案......

SELECT x.id 
  FROM my_table x 
 WHERE diagnosis IN ('d1','d2') 
 GROUP 
    BY id 
HAVING COUNT(*) =2;
+----+
| id |
+----+
|  1 |
|  3 |
+----+
2 rows in set (0.00 sec) <-- ANSWER!!!

Answer 3

这可能会有所帮助..我已经更新了..

select count(*) as TOTAL from TABLE_NAME where Diagnosis in ('d1', 'd2') group by Diagnosis

Answer 4

你已经非常模糊地写了你的问题，但我认为你想要在MSSQL下面的解决方案：

select COUNT(1) from 
(
    select distinct(id) from my_table where Diagnosis = 'd1'
    intersect
    select distinct(id) from my_table where Diagnosis = 'd2'
) as TempResultset

如果单独运行内部查询，您将获得ID。

如何计算哪个id具有其他列的值的id

4 个答案: