Question

我们有以下要求

我需要处于活动状态的customer_name，并且indore，Mumbai中的attribute_name = City和attribute_value，结果应返回小于等于2的计数

这意味着从印多尔（Indore）的结果中我应该得到3的2个结果，对于孟买，我应该从1中得到1的结果。

我尝试了以下两种方法，但为印多尔和孟买的客户获取了所有行

客户表格具有以下详细信息

customer_id customer_name customer_Status ------------------------------------------ 1 ABC Active 2 XYZ Active 3 PQR NA 4 ABCD Active 4 ABCDE Active

customer_details 表具有以下详细信息

customer_id attribute_name attribute_value ------------------------------------------ 1 City Indore 1 Phone Number 9100000000 1 Country India 2 City Mumbai 2 Phone Number 9100000001 2 Country India 3 City Delhi 3 Phone Number 9100000002 3 Country India 4 City Mumbai 4 Phone Number 9100000003 4 Country India 5 City Mumbai 5 Phone Number 9100000004 5 Country India

代码：-

select attribute_value, r.customer_name from customer_details res join lateral ( select customer_name from Customer_table where res.customer_id=customer_id and customer_Status= 'Active' limit 2 ) r on true where attribute_name= 'City' and attribute_value in ('Indore','Mumbai');

代码：-

SELECT s.customer_name,attribute_value FROM ( SELECT *, row_number() OVER (PARTITION BY customer_id ) AS rn FROM customer_details WHERE attribute_name= 'City' and attribute_value in ('Indore','Mumbai') ) e JOIN Customer_table s USING (customer_id) WHERE rn <= 2 and and customer_Status= 'Active' ORDER BY customer_id, e.rn;

Answer 1

请尝试这种方式。

select customer_name,attribute_value from (
select ct.customer_name,attribute_value,row_number() OVER (PARTITION BY attribute_value ) AS rn
from customer_table ct ,customer_details cd
where ct.customer_status = 'Active' and ct.customer_id = cd.customer_id
and attribute_name='City' and attribute_value in('Indore','Mumbai')
) as t
where rn <= 2

Answer 2

这种设计会扼杀您希望吸引客户的任何性能。我要做的第一件事是将customer_details表和phone_number，城市和国家/地区列删除到customers表中。缺乏我将创建一个将客户连接到customer_details的视图，该视图中包含所有列。

create view Customer_Standard as 
    select c.cust_id, c.name, c.status, ph.attribute_value phone_number, ct.attribute_value city, cn.attribute_value country
      from customers c
      left join  customer_details ph on (ph.cust_id = c.cust_id and ph.attribute_name = 'Phone Number')
      left join  customer_details ct on (ct.cust_id = c.cust_id and ct.attribute_name = 'City')
      left join  customer_details cn on (cn.cust_id = c.cust_id and cn.attribute_name = 'Country') ;

然后您要的查询变为：

select cust_id, name, status, phone_number, city, country
  from (select cs.*, row_number() over (partition by city order by cust_id) rn
          from Customer_Standard cs
       ) cust
 where city in ('Indore','Mumbai')
   and rn<3;

要求有多个客户的结果以及城市名称

代码：-

代码：-

2 个答案: