为两个商店中存在的每个 product_id 显示 purchase_date

Question

我想为每个 product_id 显示两个商店 中商店 A 和商店 B 中的 purchase_date分开两列，而不是按行显示。

Main_table

product_id   store  purchase_date
44343        A      2019-01-01
44343        B      2019-01-03
23234        A      2019-02-01
23234        B      2019-02-02
55433        A      2019-01-15
55433        B      2019-01-16
22324        A      2019-01-01
74456        B      2019-01-01

Output_table

product_id    purchase_date_storeA   purchase_date_storeB
44343              2019-01-01        2019-01-03
23234              2019-02-01        2019-02-02
55433              2019-01-15        2019-01-16

这是我迄今为止尝试过的方法，但没有成功：

select 
purchase_date,
product_id,
case when store = 'A' then purchase_date end as purchase_date_storeA,
case when store = 'B.' then purchase_date end as purchase_date_storeB


from main_table

Answer 1

使用GROUP BY和HAVING如下：

select 
product_id,
max(case when store = 'A' then purchase_date end) as purchase_date_storeA,
max(case when store = 'B' then purchase_date end) as purchase_date_storeB
from main_table
where store in ('A','B')
group by product_id
having count(distinct store) = 2

为两个商店中存在的每个 product_id 显示 purchase_date

Display purchase_date for each product_id that exists in both stores

sql

presto