[英]Transform select count(*) inside a inner join
My problem here is that i'm modifying an existing query and i cannot use count(*) in the query. 我的问题是我正在修改现有查询,并且无法在查询中使用count(*)。 I have to use inner join subqueries.
我必须使用内部联接子查询。
What i need to "transform" into my inner join is like this (this works): 我需要将“转换”成我的内部联接的方式是这样的(这可行):
SELECT count(distinct t1.id)
FROM table1 t1
WHERE t1.column1 = 'value1' AND
t2.column2 = 'value2' AND
EXISTS(select 1 from table2 t2 where t2.id = t1.id)
My global query looks like this: 我的全局查询如下所示:
SELECT [many many column]
FROM table2 t2
INNER JOIN [...]
LEFT OUTER JOIN [...]
--[I NEED MY COUNT HERE, see below for example]
WHERE [some conditions are true]
ORDER BY [some column]
What i found to help me is something like this: 我发现可以帮助我的事情是这样的:
SELECT [many many column], myJoin.Count
FROM table2 t2
INNER JOIN (
SELECT tt2.id, count(distinct tt2.id) as Count
FROM table2 tt2
WHERE EXISTS (SELECT 1 FROM table1 tt1 where tt1.id = tt2.id)
GROUP BY tt2.id) myJoin
on t2.id = myJoin.id;
See what i'm trying to acheive? 看到我要达到的目标吗? I need to count the ids, joining 2 tables, but i can't have a count in my main query, i can't possibly copy-paste all the "group by" condition that would go with it... I'm on sql server.
我需要计算ID,加入2个表,但是我无法在主查询中进行计数,我不可能复制粘贴所有与之匹配的“分组依据”条件...我在sql server上。
If i find the answer i will come back and post it. 如果我找到答案,我会回来并发布它。 Thanks for any advice/tricks about this.
感谢您的任何建议/技巧。
How about the following: 怎么样:
SELECT table2.*, TopQ.MyCount
FROM (
SELECT t2.id, myJoin.MyCount
FROM table2 t2
INNER JOIN (
SELECT tt2.id, count(distinct tt2.id) as MyCount
FROM table2 tt2
WHERE EXISTS
(SELECT 1 FROM table1 tt1 where tt1.id = tt2.id)
GROUP BY tt2.id) AS myJoin
on t2.id = myJoin.id
)AS TopQ
INNER JOIN table2 ON TopQ.id = table2.id
I came across this: 我遇到了这个:
select count(distinct t1.id) over (partition by t1.aColumn) as myCount,
[many many column]
from table2 t2
inner join table1 t1 on [someConditions] = value1 and
[someConditions] = value2 and
t2.id = t1.id;
I get the same results as my first select i posted in my question, and without adding a "group by" anywhere and a lot of inner join that im not that familliar with. 我得到的结果与我在问题中发布的第一次选择的结果相同,并且没有在任何地方添加“分组依据”以及很多不那么熟悉的内部联接。 I'm gonna stick with this solution.
我要坚持这种解决方案。 Thanks!
谢谢!
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