Sql 选择在某一天访问过所有课程的所有成员

我正在尝试创建一个查询，选择所有具有“黄金”状态的成员，并参加了所有在周日举行的课程

这将是我的select语句：

SELECT member_ID, first_name, last_name
FROM member
         JOIN person p on member.fk_person = p.person_ID
         JOIN enrolment e on member.member_ID = e.fk_member_ID
         JOIN membership m on member.fk_membership = m.membership_ID
         JOIN class c on e.fk_class_ID = c.class_ID
WHERE status = 'GOLD'
GROUP BY member_ID, first_name, last_name
HAVING COUNT(*) = (SELECT COUNT(*) FROM class WHERE weekday = 'SUNDAY');

以下语句返回两个发生在星期天的类：

SELECT count(class_id)
FROM class
WHERE weekday = 'SUNDAY';

SELECT member_ID, first_name, last_name
FROM member
         JOIN person p on member.fk_person = p.person_ID
         JOIN enrolment e on member.member_ID = e.fk_member_ID
         JOIN membership m on member.fk_membership = m.membership_ID
         JOIN class c on e.fk_class_ID = c.class_ID
WHERE status = 'GOLD' AND weekday = 'SUNDAY'
GROUP BY member_ID, first_name, last_name
HAVING COUNT(*) = (SELECT COUNT(*) FROM class WHERE weekday = 'SUNDAY');

我在上面的select语句是不是错了？我应该做什么来实现我的目标

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整个SQL脚本在此处可用：

您需要在查询的主要部分设置

计数条件，以便它也仅在星期天计算类数：

SELECT count(class_id)
FROM class
WHERE weekday = 'SUNDAY';

SELECT member_ID, first_name, last_name
FROM member
         JOIN person p on member.fk_person = p.person_ID
         JOIN enrolment e on member.member_ID = e.fk_member_ID
         JOIN membership m on member.fk_membership = m.membership_ID
         JOIN class c on e.fk_class_ID = c.class_ID
WHERE status = 'GOLD' AND weekday = 'SUNDAY'
GROUP BY member_ID, first_name, last_name
HAVING COUNT(*) = (SELECT COUNT(*) FROM class WHERE weekday = 'SUNDAY');

输出（用于示例数据）

我认为您只是缺少了一个WHERE谓词，用于只过滤周日有类的对象（以便计数（*）正确工作）：

嗨，我能帮你做一个数据库结构的ER图吗？这和我已经发布的答案有什么不同吗？我在你之前就开始打字了-没有答案。只是一个并行性问题。我想没什么事打扰你