如何查找每个客户的不同电话数量并根据计数将客户(计数)放入不同的桶中?

How to find number of distinct phones per customer and put the customers(counts) in different buckets as per the counts?

下面是 table,我有 customer_id 和他们有不同的 phone。

customer_id     phone_number
101            123456789
102            234567891
103            345678912
102            456789123
101            567891234
104            678912345
105            789123456
106            891234567
106            912345678
106            456457234
101            655435664
107            453426782

现在,我想找到 customer_id 和不同的 phone 数字计数。
所以我使用了这个查询:

select distinct customer_id ,count(distinct phone_number)
from customer_phone;

customer_id   no of phones
101            3
102            2
103            1
104            1
105            1
106            3
107            1

并且,从上面 table 我的最终目标是实现下面的输出,它获取计数并放入不同的桶中,然后计算落入这些桶中的消费者数量。

Buckets no of consumers
3         2
2         1
1         4

有近2亿条记录。您能否解释一下解决此问题的有效方法?

使用两个聚合:

select cnt, count(*), min(customer_id), max(customer_id)
from (select customer_id, count(distinct phone_number) as cnt
      from customer_phone
      group by customer_id
     ) c
group by cnt
order by cnt;

您可以使用 width_bucket

select bucket, count(*)
from (
  select width_bucket(count(distinct phone_number), 1, 10, 10) as bucket
  from customer_phone
  group by customer_id
) t
group by bucket;

width_bucket(..., 1, 10, 10) 为值 1 到 10 创建十个桶。

在线示例:http://dbfiddle.uk/?rdbms=oracle_11.2&fiddle=1e6d55305570499f363837aba21bdc7e