文本的 SQL 查询问题（嵌套不存在）

Question

我已经为此苦苦挣扎了一段时间，所以也许有人可以提供一些见解。

我们有一个来自 TVShow 数据库的练习查询，对于这个问题有 4 个表。

查询如下：赞助 ABC 的所有电视节目的赞助商

到目前为止我尝试过的是这样，但它似乎不起作用：

SELECT DISTINCT RSPONSOR.SPONSOR_NAME FROM RSPONSOR WHERE NOT EXISTS ( SELECT * FROM RTVSHOW WHERE NOT EXISTS ( SELECT * FROM RSPONSORBY WHERE RSPONSOR.SPONSOR_NAME = RSPONSORBY.SPONSOR_NAME AND RSPONSORBY.SHOW_NUM = RTVSHOW.SHOW_NUM AND RTVSHOW.NETWORK_ID = 'ABC' ) );

希望有任何帮助！提前致谢。

以下是供参考的表格

--RTVSHOW--

SHOW_NUM    NUMBER

SHOW_NAME   VARCHAR2(20 BYTE)

START_MONTH NUMBER

START_YEAR  NUMBER

END_MONTH   NUMBER

END_YEAR    NUMBER

NETWORK_ID  VARCHAR2(20 BYTE)

DISTR_NAME  VARCHAR2(20 BYTE)

--响应者--

SPONSOR_NAME

PARENT_NAME

--RSPONSORBY--

SHOW_NUM

SPONSOR_NAME

--RNETWORK--

NETWORK_ID

NETWORK_HQ

PARENT_NAME

Answer 1

select rSponsor.sponsor_name, rSponsor.parent_name
from rSponsor
join rSponsorBy
    on rSponsor.sponsor_name = rSponsorBy.sponsor_name
join rTVShow
    on rSponsorBy.show_num = rTVShow.show_num
join rNetwork
    on rTVShow.network_id = rNetwork.network_id
where rNetwork.network_id = 'ABC'
group by rSponsor.sponsor_name, rSponsor.parent_name
having count(distinct rTVShow.show_num) = --ABC shows sponsored by this sponsor
(
    select count(distinct rTVShow.show_num) --ABC shows
    from rTVShow
    join rNetwork
        on rTVShow.network_id = rNetwork.network_id
    where
        rNetwork.network_id = 'ABC'
);