按结果出现的半径数对结果进行排序 ST_DWithin

Question

我有 table 个现有客户和另一个 table 个潜在客户。我想 return 一个潜在客户列表，按他们出现在现有购买者的半径数量排序。

每个现有客户的潜在客户 table 中有很多行，给定现有客户周围的半径可能包含多个潜在客户。我想要 return 一个潜在客户列表，这些潜在客户按他们所属的现有客户半径的数量排序。

SELECT pur.contact_id AS purchaser, count(pot.*) AS nearby_potential_customers 
FROM purchasers_geocoded pur, potential_customers_geocoded pot 
WHERE ST_DWithin(pur.geom,pot.geom,1000)
GROUP BY purchaser;

有人对如何进行有任何建议吗？

编辑：

在一些帮助下，我编写了这个查询，它似乎可以完成工作，但我现在正在验证。

WITH prequalified_leads_table AS (
   SELECT *
   FROM nearby_potential_customers
   WHERE market_val > 80000
   AND   market_val < 120000
   )
, proximate_to_existing AS (
   SELECT pot.prop_id AS prequalified_leads
   FROM purchasers_geocoded pur, prequalified_leads_table pot
   WHERE ST_DWithin(pot.geom,pur.geom,100)
  )
SELECT prequalified_leads, count(prequalified_leads)
FROM proximate_to_existing
GROUP BY prequalified_leads
ORDER BY count(*) DESC;

Answer 1

I want to return a list of potential customers ordered by the count of the existing customer radii that they fall within.

您的查询尝试了与您的陈述相反的方法，将现有客户周围的潜在客户计算在内。
反转它，并在添加一些调整后：

SELECT pot.contact_id AS potential_customer
     , rank() OVER (ORDER BY pur.nearby_customers DESC
                           , pot.contact_id) AS rnk
     , pur.nearby_customers 
FROM   potential_customers_geocoded pot
LEFT   JOIN LATERAL (
   SELECT count(*) AS nearby_customers 
   FROM   purchasers_geocoded pur
   WHERE  ST_DWithin(pur.geom, pot.geom, 1000)
   ) pur ON true
ORDER  BY 2;

我建议使用 LEFT JOIN LATERAL ... ON true 的子查询来获取计数。应该利用你无疑拥有的空间索引：

CREATE INDEX ON purchasers_geocoded USING gist (geom);

从而在结果中保留具有 0 个附近客户的行 - 您的原始连接样式将排除那些。相关：

然后 ORDER BY 外部查询中的结果 nearby_customers（不是：~~nearby_potential_customers~~）。

不清楚您是否要添加一个实际的 rank。如果是这样，请使用 window function rank()。我在使用时确定了排名，用一个额外的 ORDER BY 表达式打破了联系：pot.contact_id。否则，对等点以任意顺序返回，每次执行都可以更改。

ORDER BY 2 是 "order by the 2nd out column" 的缩写语法。参见：

Select first row in each GROUP BY group?

按结果出现的半径数对结果进行排序 ST_DWithin

Rank order ST_DWithin results by the number of radii a result appears in

sql

postgresql

postgis

aggregate

rank