了解联接

Question

我正在尝试从数据库中获取行，其中id不等于从链接表返回id。可以使用连接完成吗？

select *
    from module_items_profile people
        where people.item_id not in (
            select link.people_id
                    from link_page_people link 
                        where link.page_id = $page_id
                        )

Answer 1

是的，但使用带有LEFT JOIN谓词的IS NULL：

select *
from module_items_profile AS people
LEFT JOIN
(
  SELECT * 
  FROM link_page_people 
  where page_id = $page_id
) AS link ON people.item_id = link.people_id
WHERE link.people_id IS NULL;