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我有两张桌子:画廊和图片:

画廊

id           int (auto increment, primary key)
name         varchar

图片

id           int (auto increment, primary key)
picture      varchar
gallery_id   int (foreign key)

如何连接这两个表,显示左表(图库)中每一行只是第二个表的第一行,而没有遍历第二个表中的所有行？我正在使用MySQL.

我的目标是创建一个页面,其中包含显示每个图库的图片的现有图库列表,作为指向详细信息页面的链接以及该图库的所有图片.

我在这个网站上搜索过这个问题,但类似的问题太复杂了.我只对这个简单的例子感兴趣.

我有一个复杂的查询：

SELECT DISTINCT ON (delivery.id)
delivery.id, dl_processing.pid
FROM mailer.mailer_message_recipient_rel AS delivery
    JOIN mailer.mailer_message AS message ON delivery.message_id = message.id
    JOIN mailer.mailer_message_recipient_rel_log AS dl_processing ON dl_processing.rel_id = delivery.id AND dl_processing.status = 1000
    -- LEFT JOIN mailer.mailer_recipient AS r ON delivery.email = r.email
    JOIN mailer.mailer_mailing AS mailing ON message.mailing_id = mailing.id
WHERE
    NOT EXISTS (SELECT dl_finished.id FROM mailer.mailer_message_recipient_rel_log AS dl_finished WHERE dl_finished.rel_id = delivery.id AND dl_finished.status <> 1000) AND
    dl_processing.date <= NOW() - (36000 * INTERVAL '1 second') AND
    NOT EXISTS (SELECT …