具有左联接和计算计数的Clickhouse阵列联接

问题描述

我有一个SearchImpressions表，该表具有一个嵌套的类型列，其中包含在搜索过程中显示的Product_Id和Price数组。我还有一个表格，其中包含用户单击搜索结果之一时的详细信息。

问题：

给出一个产品ID，我想找出按天分组的总印象数和点击次数。

产品搜索结果表

EventDateTime查询结果（ProductId []，Price []）

产品点击次数表

EventDateTime产品ID

必需的输出

EventDate    ProductId TotalImpressions TotalClicks

11-11-2020   0001      56               6
12-11-2020   0002      21               0

我已经尝试过，但是两个计数看起来都一样

SELECT pr.EventDate,impressions.ProductId,count(impressions.ProductId) As TotalImpressions,count(clicks.productId) as TotalClicks
FROM ProductResults pr
ARRAY JOIN results as impressions
LEFT JOIN ProductClicks clicks on
          impressions.ProductId = clicks.ProductId
GROUP BY pr.EventDate,pr.DealershipId,pr.Vrm
ORDER BY pr.EventDate Desc;

谢谢

解决方法

看来需要为 clicks.productId 的计数汇总函数添加谓词，或使用uniqIf-function：

SELECT pr.EventDate,impressions.ProductId,count(impressions.ProductId) As TotalImpressions,countIf(clicks.productId != 0) as TotalClicks1 /* <-- v.1 */
       uniqIf(clicks.productId,clicks.productId != 0) as TotalClicks2 /* <-- v.2 */
..

,

 SELECT pr.EventDate,count() As TotalImpressions,clicks.TotalClicks
 FROM ProductResults pr ARRAY JOIN results as impressions
 LEFT JOIN    (select ProductId,count(clicks.productId) TotalClicks 
               from  ProductClicks group by ProductId 
              ) clicks on impressions.ProductId = clicks.ProductId
 GROUP BY pr.EventDate,impressions.ProductId
 ORDER BY pr.EventDate Desc;