mysql选择计数联合 [英] mysql select count union

问题描述

我有这样的：

(SELECT COUNT(*) AS total FROM `transactions` WHERE 
   `asset`='u_{$user_id}' GROUP BY id)
 UNION DISTINCT 
(SELECT COUNT(*) AS total FROM transactions tr 
   INNER JOIN payments pa ON tr.asset = CONCAT('p_', pa.id) 
   WHERE pa.user_id = '{$user_id}' 
   GROUP BY tr.id)

它提供 1

/ p>

Now works like this:

SELECT
 (SELECT COUNT(*) FROM `transactions` 
    WHERE `asset`='u_{$user_id}')
  + 
 (SELECT COUNT(*) FROM transactions tr 
    INNER JOIN payments pa ON tr.asset = CONCAT('p_', pa.id) 
    WHERE pa.user_id = '{$user_id}')

它提供 6

但我需要得到 5 ..查询？

But i need to get 5.., sow how to make a right query?

当然，我可以通过php，但是...通过sql ..

Sure, i can do this by php, but..HOW by sql..?

真的和和或条件无关紧要，他们工作正常，问题在于计算UNION的查询。第二个查询正确地计数summ（1 + 5），但值与查询相交。第一个给出第一个子查询的结果。所以，我需要唯一的结果之前计数...

Really "and" and "or" conditions does not matter, they works correctly, the problem is in counting UNION`ed query. The second query correctly counts summ (1+5), but values ​​intersect queries. The first one gives result of just first subquery. So, i need to unique results before count...

在php，它应该看起来像：我通过内部联接支付交易id列表，长整型查询在一个循环中，得到类似 SELECT COUNT（*）FROM transaction WHERE（*我现在有* OR id = $ id_1或id = $ id_2或id = $ id_3等）

In php, it should look like that: i get transactions id list by inner join with payments, than construct a long query in a loop, to get something like SELECT COUNT(*) FROM transactions WHERE (*what i have now* OR id=$id_1 OR id=$id_2 OR id=$id_3 etc..)

UPD：cutted

RESOLVED！ =）

SELECT COUNT(*) FROM(
SELECT tr.* FROM transactions tr 
WHERE tr.asset='u_{$user_id}' OR (tr.liability='g' AND tr.l_info='{$user_name}')
UNION SELECT tr.* FROM transactions tr 
INNER JOIN payments pa ON tr.asset = CONCAT('p_', pa.id) 
WHERE pa.user_id = '{$user_id}' AND pa.status='100') 
AS total

总计

推荐答案

我经历了你的问题，我想你想从联合子句获取最大值，我不知道的mySql，所以我已经解决了你的问题在MS-SQL。

I gone through your question, and i think you want to fetch the maximum from the union clause, well i am not aware of the mySql, so i have solved your question in MS-SQL.

逻辑： - 我使用CTE，然后执行UNION操作，然后我选择MAXIMUM两个。

Logic:- I have used CTE, and afterwards performed UNION operation and then i have selected MAXIMUM from the two.

WITH COUNTT AS (SELECT 1 AS TEST
UNION 
SELECT 5 AS TEST)
SELECT MAX(TEST) FROM COUNTT

代替硬编码的1 5，你可以使用你的计数查询，我认为这是你正在寻找。并且，请将其标记为答案。

And, in place of hardcoded "1" and "5", you can use your count query, i think it is what you are looking for. And, please mark it as an answer.

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