Mysql 查找所有值'；x'；不包含'；y'；

我必须提供所有活动的

站点的列表，这些站点不包含
域

SELECT companies.name,sites.name,sites.association 
FROM companies JOIN sites ON sites.company = companies.id 
JOIN domains ON domains.site != sites.id WHERE sites.is_deleted = 0 
AND domains.is_primary = 1 AND domains.is_deleted = 0

我加入的条件是
站点
的主键与
域.site
字段中的任何内容都不对应。然而，我知道我没有得到我需要的输出，因为我知道我想要的数量或行，并且我正在生成更多

我正在使用的te模式的uml图是（有点古怪）。
如果您试图查找没有主域的站点，这可能会提供您所需要的。它使用左连接并检查域记录是否为空/缺失

SELECT  companies.name,
        sites.name,
        sites.association
FROM    companies
        JOIN sites ON sites.company = companies.id
        LEFT JOIN domains ON domains.site = sites.id
                             AND domains.is_primary = 1
                             AND domains.is_deleted = 0
WHERE   sites.is_deleted = 0
        AND domains.id IS NULL

也可以考虑使用不存在< /P>
SELECT  companies.name,
        sites.name,
        sites.association
FROM    companies
        JOIN sites ON sites.company = companies.id
WHERE   sites.is_deleted = 0
        AND NOT EXISTS (
            SELECT 1
            FROM    domains d
            WHERE   d.site = sites.id
                    AND d.is_primary = 1
                    AND d.is_deleted = 0
        )

这里有一个sql FIDLE供您测试
假设您试图查找没有主域的站点，那么这可能会提供您所需的内容。它使用左连接并检查域记录是否为空/缺失

SELECT  companies.name,
        sites.name,
        sites.association
FROM    companies
        JOIN sites ON sites.company = companies.id
        LEFT JOIN domains ON domains.site = sites.id
                             AND domains.is_primary = 1
                             AND domains.is_deleted = 0
WHERE   sites.is_deleted = 0
        AND domains.id IS NULL

也可以考虑使用不存在< /P>
SELECT  companies.name,
        sites.name,
        sites.association
FROM    companies
        JOIN sites ON sites.company = companies.id
WHERE   sites.is_deleted = 0
        AND NOT EXISTS (
            SELECT 1
            FROM    domains d
            WHERE   d.site = sites.id
                    AND d.is_primary = 1
                    AND d.is_deleted = 0
        )

这里有一个sql FIDLE供您测试
请不要看图片，谢谢。请不要看图片，谢谢。
域.id
字段不包含任何空值，这是此查询让我发疯的原因。
域.id
字段不包含任何空值，这也是此查询让我发疯的原因之一