sql - SQL查询逻辑多条记录

Question

我需要创建一个查询来返回 Customer_ID 具有多个与之关联的 Prospect_ID 的行。例如，我希望查询是 ale 以返回下面的第 2 行和第 3 行，因为 Customer_ID 是相同的，但 Prospect_ID 不同，但不是第 5 行和第 6 行，因为 Prospect_id 是相同的：

Prospect_ID   Customer_ID
1001          31001
1002          31002
1003          31002
1004          31003
1005          31004
1005          31004 

Answer 1

要获得Customer_id多个不同的Prospect_id：

select customer_id
from yourtable
group by customer_id
having count(distinct prospect_id) >1

请参阅带有演示的 SQL Fiddle

如果您想返回所有详细信息，Customer_Ids则可以使用：

select *
from yourtable t1
where exists (select customer_id
              from yourtable t2
              where t1.customer_id = t2.customer_id
              group by customer_id
              having count(distinct prospect_id) >1)

请参阅SQL Fiddle with Demo。

这也可以写成（感谢@ypercube）：

select *
from yourtable t1
where exists (select customer_id
              from yourtable t2
              where t1.customer_id = t2.customer_id
              and t1.prospect_id <> t2.prospect_id)

请参阅带有演示的 SQL Fiddle

Answer 2

您可以使用窗口函数执行此操作：

select prospect_id, customer_id
from (select t.*,
             COUNT(*) over (partition by prospect_id, customer_id) as cnt_pc,
             COUNT(*) over (partition by customer_id) as cnt_c
      from t
     ) t
where cnt_pc <> cnt_c and cnt_c > 1