[英]Combine multiple queries into one query
I am trying to group by clientid
and m.id
. 我正在尝试按
clientid
和m.id
。 How can I convert these 2 queries into 1 query? 如何将这2个查询转换为1个查询?
Query 1 查询1
select cs.clientid, count(distinct(m.id)) as cp
into #temp
from call_table cs
join mem_table m
on cs.CLIENTID = m.clientid
join activity_table a
on a.memid = m.id
where a.activity = 'abc'
group by cs.clientid, m.id
Query 2 查询2
select clientid, sum(cp) from #temp
group by ClientId
Update 更新
More specifically, I am looking to write this query without using a temp table. 更具体地说,我希望在不使用临时表的情况下编写此查询。
You could group only by clientid 您只能按clientid分组
And since no fields from activity_table are selected, an EXISTS can be used instead. 并且由于没有选择来自activity_table的字段,因此可以使用EXISTS代替。
select cs.clientid, count(distinct m.id) as cp
from call_table cs
join mem_table m on m.clientid = cs.clientid
where exists
(
select 1
from activity_table a
where a.memid = m.id
and a.activity = 'abc'
)
group by cs.clientid
Why wouldn't you just write this as: 你为什么不这样写:
with temp as (
select cs.clientid, count(distinct m.id) as cp
from call_table cs join
mem_table m
on cs.CLIENTID = m.clientid join
activity_table a
on a.memid = m.id
where a.activity = 'abc'
group by cs.clientid, m.id
)
select clientid, sum(cp)
from temp
group by ClientId;
I can't figure out what the logic should really be, but this seems like the simplest way to combine the queries. 我无法弄清楚逻辑究竟应该是什么,但这似乎是组合查询的最简单方法。
I would speculate that you simply want this query: 我推测您只需要此查询:
select cs.clientid, count(distinct m.id) as cp
from call_table cs join
mem_table m
on cs.CLIENTID = m.clientid join
activity_table a
on a.memid = m.id
where a.activity = 'abc'
group by cs.clientid;
That is, remove m.id
from the group by
. 也就是说,通过将该
m.id
从group by
删除。 And this can in turn be simplified to: 而这又可以简化为:
select m.clientid, count(distinct m.id) as cp
from mem_table m join
activity_table a
on a.memid = m.id
where a.activity = 'abc'
group by cs.clientid;
Assuming that m.id
is unique and non- NULL
, this can be further simplified to: 假设
m.id
是唯一且非NULL
,则可以进一步简化为:
select m.clientid, count(*) as cp
from mem_table m join
activity_table a
on a.memid = m.id
where a.activity = 'abc'
group by cs.clientid;
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