mysql - MySQL 中的相同值未分组

Question

我在两个单独的表(均为 varchar(45))中有两列，并且它们都有诸如 0123456 之类的值。

我有一个联合查询，它基本上堆叠两个表中的行。

select 
'ISSUED' AS action,
card_match_key AS card_match_key,
count(0) AS CNT
from
dim_consumer_cards
group by 1 , 2 

union 

select 
'REDEEMED' AS action,
card_match_key AS card_match_key,
count(0) AS CNT
from
fct_card_redemptions
group by 1 , 2

然后是第二个查询，它在堆叠数据上形成交叉表。

Select
card_match_key as cardkey,
sum(case when action = 'ISSUED' then CNT else 0 end) as ISSUED,
sum(case when action = 'REDEEMED' then CNT else 0 end) as REDEEMED
from vw_rpt_matchkey1
group by 
card_match_key

我的问题是我的值没有按相似的值分组(例如 0123456)。每个值应该只出现在一行上，但我得到了两行。

Answer 1

尝试更改您的第一个查询以使用通用子表达式，如下所示:

with (
     select 
     'ISSUED' AS action,
     card_match_key AS card_match_key,
     from
     dim_consumer_cards
     UNION ALL
     select 
     'REDEEMED' AS action,
     card_match_key AS card_match_key,
     from
     fct_card_redemptions) AS combined
select action, card_match_key, count(1) as CNT
from combined
group by 1,2;

在进行分组之前，需要先进行并集操作。