加入過濾器不能按預期在MySQL中工作

Question

我已經寫了一個MySQL查詢（廣告旋轉算法）從多個表中獲取記錄。

select Q2.* 
from User u,(
    select 
     a.adId as "AdId", 
     a.UserId as "UserId", 
     a.Title as "Title", 
     a.ImageURL as "ImageURL", 
     a.RefURL as "RefURL", 
     a.CreateDate as "CreateDate", 
     a.StartDate as "StartDate", 
     a.RunTill as "RunTill", 
     a.Budget as "Budget", 
     a.Status as "Status", 
     (a.budget - COALESCE(Q1.A2,0)) as "Remaining" 
    from Ad a 
    LEFT JOIN(
     select 
      AdId as A1, 
      count(*) as A2 
     from Referral 
     where date(ReferralDate)=date(CURRENT_TIMESTAMP) 
     group by AdId 
    ) as Q1 
    ON a.AdId = Q1.A1 
    and a.StartDate<CURRENT_TIMESTAMP 
    and a.RunTill>CURRENT_TIMESTAMP 
    and a.Status = 1 
) as Q2 
where u.Authorized = true 
and u.Balance>1 
and u.UserId = Q2.UserId 
order by Q2.Remaining desc; 

上面的查詢有一個過濾器a.Status = 1，但結果是，我越來越有狀態行！= 1爲好。結果集如下：

+--------------+--------------+--------------------------------+----------------------------------------------------------------+--------------------------------+--------- 
------------+---------------------+---------------------+--------+--------+-----------+ 
| AdId   | UserId  | Title       | ImageURL              | RefURL       | CreateDa 
te   | StartDate   | RunTill    | Budget | Status | Remaining | 
+--------------+--------------+--------------------------------+----------------------------------------------------------------+--------------------------------+--------- 
------------+---------------------+---------------------+--------+--------+-----------+ 
| 382944516829 | 724511865288 | Online Advertising for Nepal | /static/image/adimage/noimage.jpg        | http://www.nepaladz.com  | 2011-11- 
03 13:47:47 | 2011-11-03 00:00:00 | 2011-11-30 00:00:00 | 100 |  0 |  100 | 
| 973252821643 | 724511865288 | Models, news, fashion and more | http://nepalads.servehttp.com:8080/static/image/adimage/7.jpg | http://www.cybersansar.com  | 2011-10- 
18 15:57:49 | 2011-11-03 10:59:57 | 2011-11-18 15:57:49 |  70 |  1 |  70 | 
| 805400799468 | 724511865288 | Alibaba market     | http://nepalads.servehttp.com:8080/static/image/adimage/4.jpg | http://www.alibaba.com   | 2011-10- 
18 15:54:42 | 2011-11-03 10:59:57 | 2011-11-18 15:54:42 |  60 |  1 |  60 | 
| 333179565363 | 724511865288 | Nepal AT&T Network    | http://nepalads.servehttp.com:8080/static/image/adimage/3.jpg | http://www.att.com    | 2011-10- 
18 15:54:00 | 2011-11-03 10:59:57 | 2011-11-18 15:54:00 |  60 |  1 |  60 | 
| 576540783739 | 724511865288 | Travel with us!    | http://nepalads.servehttp.com:8080/static/image/adimage/8.jpg | http://www.manang.com   | 2011-10- 
18 15:58:39 | 2011-11-03 10:59:57 | 2011-11-18 15:58:39 |  45 |  1 |  43 | 
| 011731192504 | 724511865288 | Nepal Online Shopping   | http://nepalads.servehttp.com:8080/static/image/adimage/11.jpg | http://www.harilo.com   | 2011-10- 
18 16:02:32 | 2011-11-03 10:59:57 | 2011-11-18 16:02:32 |  45 |  1 |  42 | 
| 232044045570 | 724511865288 | Himalayan Java     | http://nepalads.servehttp.com:8080/static/image/adimage/1.jpg | http://www.himalayanjava.com | 2011-10- 
18 15:51:34 | 2011-11-03 10:59:57 | 2011-11-18 15:51:34 |  30 |  1 |  30 | 
| 471978035014 | 724511865288 | Home TV. 50% discount   | http://nepalads.servehttp.com:8080/static/image/adimage/5.jpg | http://www.dishhome.com.np  | 2011-10- 
18 15:56:03 | 2011-11-03 10:59:57 | 2011-11-18 15:56:03 |  30 |  1 |  30 | 
| 543726500808 | 724511865288 | Live the adventure    | http://nepalads.servehttp.com:8080/static/image/adimage/9.jpg | http://www.adventuresnepal.com | 2011-10- 
18 15:59:21 | 2011-11-03 10:59:57 | 2011-11-18 15:59:21 |  25 |  1 |  25 | 
| 757765466809 | 724511865288 | Wanna meet me? Click here  | http://nepalads.servehttp.com:8080/static/image/adimage/10.jpg | http://www.missnepal.com.np | 2011-10- 
18 16:00:14 | 2011-11-03 10:59:57 | 2011-11-18 16:00:14 |  25 |  1 |  23 | 
| 890639256469 | 724511865288 | Learn dance from Gurus   | http://nepalads.servehttp.com:8080/static/image/adimage/6.jpg | http://www.salsanepal.com  | 2011-10- 
18 15:56:45 | 2011-11-03 10:59:57 | 2011-11-18 15:56:45 |  15 |  1 |  15 | 
| 838481835983 | 724511865288 | Fashionista Nepal    | http://nepalads.servehttp.com:8080/static/image/adimage/2.jpg | http://www.nepalfashion.com | 2011-10- 
18 15:53:06 | 2011-11-03 10:59:57 | 2011-11-18 15:53:06 |  15 |  1 |  14 | 
+--------------+--------------+--------------------------------+----------------------------------------------------------------+--------------------------------+--------- 

我該如何解決這個問題？

在此先感謝。 詹姆斯

Answer 1

您應該移動和a.Status = 1 where子句：

select Q2.* 
from User u,(
    select 
     a.adId as "AdId", 
     a.UserId as "UserId", 
     a.Title as "Title", 
     a.ImageURL as "ImageURL", 
     a.RefURL as "RefURL", 
     a.CreateDate as "CreateDate", 
     a.StartDate as "StartDate", 
     a.RunTill as "RunTill", 
     a.Budget as "Budget", 
     a.Status as "Status", 
     (a.budget - COALESCE(Q1.A2,0)) as "Remaining" 
    from Ad a 
    LEFT JOIN(
     select 
      AdId as A1, 
      count(*) as A2 
     from Referral 
     where date(ReferralDate)=date(CURRENT_TIMESTAMP) 
     group by AdId 
    ) as Q1 
    ON a.AdId = Q1.A1 
    WHERE 
     a.StartDate<CURRENT_TIMESTAMP 
    and a.RunTill>CURRENT_TIMESTAMP 
    and a.Status = 1 
) as Q2 
where u.Authorized = true 
and u.Balance>1 
and u.UserId = Q2.UserId 
order by Q2.Remaining desc; 

Answer 2

我假設的問題實際上應該是

我得到行與狀態！ = 1以及

原因是因爲您有a.Status = 1作爲LEFT JOIN的連接條件的一部分。因此，正確的解決方案將使用INNER JOIN或將該過濾器作爲where子句的一部分。