将外部分组结果用于子查询中的“IN”运算符时出现SQL错误

Question

我有以下查询尝试使用外部聚合结果作为子查询的输入（在这种情况下in语句）：

select 
 COUNT(DISTINCT individual_id) as visitors,
 (select 
   (case when 
     SUM(case when cr2.isConverted = true then 1 else 0 end) > 0 
     then 1 else 0 end) as conv from campaigns_reporting as cr2 where 
     cr2.id in (DISTINCT cr1.id) group by individual_id) as conversions
     from campaigns_reporting as cr1 where
     isinholdback = false  and
    occurredat between '2018-02-25T18:00:00.000Z' and '2018-03-04T17:59:59.000Z' and
    customer_id = '1'
 group by campaign_id, isinholdback

我收到以下错误：

错误：“DISTINCT”或其附近的语法错误

第5行：...来自campaign_reporting为cr2，其中cr2.id为（DISTINCT c ... ^

注意：我正在使用postgresql。

提前感谢您提供任何帮助。

Answer 1

您的查询无法完成。 cr1不能在select id中使用，因为它不包含在group by中。试试这个：

select COUNT(DISTINCT individual_id) as visitors, 
   (case when sum(cr3.conv) > 0 then 1 else 0 end) as conversions
   from campaigns_reporting as cr1
   inner join 
   (select id, (case when SUM(case when cr2.isConverted = true then 1 else 0 end) > 0 then 1 else 0 end) as conv 
   from campaigns_reporting  as cr2 
   group by id) as cr3 on cr1.id= cr3.id
where isinholdback = false
and occurredat between '2018-02-25T18:00:00.000Z' and '2018-03-04T17:59:59.000Z'
and customer_id = '1'
group by campaign_id, isinholdback