SQL查询使用IN（）和强制值

Question

我有一个INNER JOIN查询其抓住取决于值的连接表一国名：

SELECT DISTINCT countryName, countrySlug 
FROM countries AS Country 
INNER JOIN countries_networks AS n ON Country.id = n.country_id 
AND n.network_id IN (6, 7, 8, 9, 14) 

不过，我现在需要select的那些符合IN（）标准，并且还必须包含网络2。

我显然不能只添加2的IN（），因为我需要2是强制性的，至少有一个其他人。

有人可以帮忙，我有一种感觉它的可笑简单。

Answer 1

试试这个（双加入？）：

SELECT DISTINCT countryName, countrySlug, n.country_id, n2.country_id 
FROM countries AS Country 
INNER JOIN countries_networks AS n ON Country.id = n.country_id 
AND n.network_id 
IN (6, 7, 8, 9, 14) 
INNER JOIN countries_networks AS n2 ON Country.id = n2.country_id 
AND n2.network_id = 2 

注：n.country_id, n2.country_id值显示只为能检查结果

Answer 2

试试这个：

SELECT DISTINCT 
    countryName, 
    countrySlug 
FROM countries AS Country 
INNER JOIN countries_networks AS n ON Country.id = n.country_id 
            AND n.network_id IN (6, 7, 8, 9, 14) 
WHERE Country.id IN (SELECT id 
        FROM countries_networks 
        WHERE network_id = 2 
         AND id IS NOT NULL); 

这将确保任何选定的国家必须有network_id = 2。

Answer 3

首先，删除DISTINCT，将EXISTS子查询替换为联接。然后，您可以添加其他子查询采取的额外要求护理：

SELECT countryName, countrySlug 
FROM countries AS c 
WHERE EXISTS 
     (SELECT * 
     FROM countries_networks AS n 
     WHERE c.id = n.country_id 
      AND n.network_id IN (6, 7, 8, 9, 14) 
    ) 
    AND EXISTS 
     (SELECT * 
     FROM countries_networks AS n 
     WHERE c.id = n.country_id 
      AND n.network_id = 2 
    ) ; 

Answer 4

只要做到这一点：

SELECT DISTINCT countryName, countrySlug 
FROM countries AS Country 
INNER JOIN countries_networks AS n ON Country.id = n.country_id 
AND n.network_id=2 And n.network_id IN (2, 6, 7, 8, 9, 14)