检查多行中是否存在一条记录

   SELECT c.*
     FROM content AS c
LEFT JOIN content_territory AS ct
       ON c.id = ct.content_id
    WHERE ct.id IN ( ... )
 GROUP BY c.id

select id, foreign_id, type, date_added
from content
where id in (select content_id from content_territory)

SELECT id, foreign_id, type, date_added
    FROM content
    WHERE EXISTS (SELECT *
                      FROM content_territory
                      WHERE content_id = content.id);