Question

这是erp.orders：

userId  paidAt
1       2017-06-30
1       2017-06-18
2       2017-06-07
4       2017-06-07
3       2017-01-01
2       2017-01-01
2       2017-01-01
2       2017-01-01

这是prod.referral_order_delivered

user_id
1
2

此请求：

select distinct erp.orders."userId", count(erp.orders."userId")
from erp.orders
inner join prod.referral_order_delivered
on erp.orders."userId"::uuid = prod.referral_order_delivered.user_id::uuid
where
   erp.orders."paidAt"::date >= '2017-06-07'
   and erp.orders."paidAt"::date <= '2017-07-07'
group by erp.orders."userId"

会给我这个结果：

userId  count
1       2
2       1

这不是我想要的结果。在2017-06-07和2017-07-07之间支付并且在表prod.referral_order_delivered中支付的ID中，我想计算它们出现在表中的次数erp.orders IN TOTAL。根据我目前的要求，我只计算2017-06-07至2017-07-07。

我想要的结果是：

userId  count
1       2
2       4

了解如何排除userId 3和4。这非常重要。你可以修改我的请求吗？

Answer 1

怎么样：

     SELECT erp.orders."userId" 
           ,count(erp.orders."paidAt")
       FROM erp.orders
 INNER JOIN prod.referral_order_delivered
         ON erp.orders."userId"::uuid = prod.referral_order_delivered.user_id::uuid
        AND erp.orders."paidAt"::date >= '2017-06-07'
        AND erp.orders."paidAt"::date <= '2017-07-07'
   GROUP BY erp.orders."userId"

Answer 2

使用having子句而不是where子句：

select o."userId", count(o."userId")
from erp.orders o inner join
     prod.referral_order_delivered rod
     on o."userId"::uuid = rod.user_id::uuid
group by o."userId"
having sum( (o."paidAt"::date >= '2017-06-07' and o."paidAt"::date <= '2017-07-07')::int) > 0;

Answer 3

尝试拆分您的问题。你想要：

2017-06-07和2017-07-07之间支付的ID以及表prod.referral_order_delivered

和

计算它们在表格中显示的次数erp.orders IN TOTAL

你已经有了前者：

select distinct erp.orders."userId"
from erp.orders inner join prod.referral_order_delivered
on erp.orders."userId"::uuid = prod.referral_order_delivered.user_id::uuid
where
   erp.orders."paidAt"::date >= '2017-06-07'
   and erp.orders."paidAt"::date <= '2017-07-07'

后者只使用内部选择：

select erp.orders."userId", count(erp.orders."userId")
from erp.orders
where
   erp.orders."userId" in (select ...)
group by erp.orders."userId"

Answer 4

当您使用内部联接时，您将在＆＃34; WHERE＆＃34;中丢弃您需要的信息。后来的条款。因为它会创建一个时间结果表，您可以在其中省略条目：

where
   erp.orders."paidAt"::date >= '2017-06-07'
   and erp.orders."paidAt"::date <= '2017-07-07'

所以你需要做的是使用半连接，如下所示：

SELECT DISTINCT erp.orders."userId", COUNT(erp.orders."userId")
FROM erp.orders
WHERE erp.orders."userId" IN (
    SELECT erp.orders."userId"
    FROM erp.orders, prod.referral_order_delivered
    WHERE erp.orders."userId"::uuid = prod.referral_order_delivered.user_id::uuid
    AND erp.orders."paidAt"::date >= '2017-06-07'
    AND erp.orders."paidAt"::date <= '2017-07-07'
);
GROUP BY erp.orders."userId"

希望它有所帮助！

选择count，内部联接和where语句

4 个答案: