联接过滤器在MySQL中无法按预期工作

Question

I have written a MySQL query (Ad rotate algorithm) to fetch records from multiple tables.

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;

The above query has a filter a.Status = 1 , but in the result, i'm getting rows with Status != 1 as well. Resultset below:

+--------------+--------------+--------------------------------+----------------------------------------------------------------+--------------------------------+---------
------------+---------------------+---------------------+--------+--------+-----------+
| 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 |
+--------------+--------------+--------------------------------+----------------------------------------------------------------+--------------------------------+---------

How can I fix this?

Thanks in advance. James

Answer 1

You should move and a.Status = 1 to a where clause:

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

I'm assuming the question should actually be

i'm getting rows with Status != 1 as well

The reason is because you have a.Status = 1 as part of the join condition of a LEFT JOIN . So the correct solution will either use an INNER JOIN or put that filter as part of a where clause.