Question

我有区域表：

table region: 
id | title

地区有很多广告：

table advert:
id | region_id | ...

然后广告有很多用途（通过表adv_use多次使用）：

table use:
use | slug   | ...
----------------
1   | slug_1 | ...
2   | slug_2 | ...
..................



table adv_use:
adv_id | use_id

我希望选择所有带有count（*）广告的区域，这些广告与slug_1 AND slug_2一起使用。如果广告与slug_1或slug_2（或两者）无关，则不得计算。我现在拥有的：

SELECT COUNT(DISTINCT advert.id) as count
FROM region
JOIN advert ON region.id = advert.region_id
JOIN adv_use ON advert.id = adv_use.adv_id
JOIN use ON adv_use.use_id = use.id
WHERE use.slug IN ('slug_1', 'slug_2')
GROUP BY region.id
HAVING COUNT(DISTINCT adv_use.use_id) = 2

但它的工作并不像我想要的那样。 SQLFiddle：http://sqlfiddle.com/#!2/5b4d4/1

感谢您的帮助，感谢抱歉英语不好。

Answer 1

您需要使用子查询来选择使用两个slugs的adv_id：

SELECT COUNT(DISTINCT advert.id) as count, region.id as reg_id
FROM region
JOIN advert ON region.id = advert.region_id
JOIN (SELECT adv_use.adv_id
      FROM adv_use
      JOIN tbl_use ON adv_use.use_id = tbl_use.id
      WHERE tbl_use.slug IN ('slug1', 'slug2')
      GROUP BY adv_use.adv_id
      HAVING COUNT(DISTINCT adv_use.use_id) = 2) adv_use
ON advert.id = adv_use.adv_id
GROUP BY region.id
;

SQLFIDDLE

MySQL JOIN + COUNT + WHERE + AND

1 个答案: