SQL查詢使用IN（）和強制值

Question

我有一個INNER JOIN查詢其抓住取決於值的連接表一國名：

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) 

不過，我現在需要select的那些符合IN（）標準，並且還必須包含網絡2。

我顯然不能只添加2的IN（），因爲我需要2是強制性的，至少有一個其他人。

有人可以幫忙，我有一種感覺它的可笑簡單。

Answer 1

試試這個（雙加入？）：

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值顯示只爲能檢查結果

Answer 2

試試這個：

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); 

這將確保任何選定的國家必須有network_id = 2。

Answer 3

首先，刪除DISTINCT，將EXISTS子查詢替換爲聯接。然後，您可以添加其他子查詢採取的額外要求護理：

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

只要做到這一點：

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)